Cold spring cabin gas concentration detection device and detection method

Abstract

The invention relates to a device and a method for detecting the gas concentration of a cold spring cabin, and belongs to the technical field of instrument testing and testing. The method comprises the following steps: carrying out water-gas separation on a cold spring cabin solution by virtue of a multi-stage separation membrane, synchronously recording the volume of separated gas and liquid by virtue of a flow meter, pressurizing by virtue of a gas booster pump, storing mixed gas by virtue of a gas storage tank, detecting the volume fraction by virtue of a gas chromatograph, and inverting the gas concentration in the solution on the basis of separated volume data; the vacuum pump, the electromagnetic valve and the control module are integrated, rapid detection and high-precision calculation are achieved, the problems that in the prior art, pretreatment time is long, and volume concentration inversion is inaccurate are solved, and the device is suitable for gas concentration detection of deep sea simulation cabins and other sealed environments.

Description

Technical Field

[0001] The invention relates to the technical field of instrumentation testing and experimentation, in particular to a cold spring chamber gas concentration detection device and a detection method. Background Art

[0002] Cold spring ecosystem refers to the unique ecological environment and biological community formed in the deep-sea cold spring area. Cold spring research is of great significance in the study of the origin of life, resource development and environmental protection in extreme environments, geophysical and chemical research, and other fields. Through the cold spring simulation chamber, the high-pressure environment of the seabed is artificially reshaped, and simulated sediment layers and deep seawater layers are constructed. By constructing the migration mode of media such as methane, an artificial physical and chemical environment of the cold spring area is established, thereby realizing the artificial cultivation of the cold spring area ecosystem. By further artificially intervening in the various physical and chemical parameters in the chamber, scientists can carry out simulation experiments in the cold spring area, more accurately obtain the impact of changes in various parameters on the seabed ecosystem, and then continue to deeply understand the impact of the development of deep-sea methane hydrate on the marine ecosystem and even the huge ecosystem of the earth.

[0003] For the measurement of the concentration of various gas media in the solution of the cold spring simulation chamber, the more common method at present is to use gas chromatography detection for quantitative analysis, but the current measurement method still needs to be improved:

[0004] First, rapid detection cannot be achieved. Before the gas chromatograph detects the solution samples in the cold spring simulation chamber, it often needs to go through pre-treatment steps such as sampling, transportation, and headspace. This process often takes a lot of time, resulting in untimely gas concentration detection. After the solution samples have undergone the above treatment, some interference factors will be introduced, such as physical and chemical reactions, gas escape, pollution, etc., which will have an adverse effect on the accuracy of gas concentration measurement;

[0005] Second, the volume concentration cannot be accurately inverted to the concentration of the solution in the cabin. During scientific experiments in the cold spring simulation cabin, it is necessary to obtain the concentration of each gas component in the cold spring cabin solution at any time for adjustment. Gas chromatography detection obtains the chromatographic peak area of various gases based on instrument detection. Combined with the pre-prepared standard curve, it can only obtain the volume fraction of various gases, that is, the volume ratio of each component gas to the mixed gas; how to accurately obtain the concentration of the gas solution through the volume fraction needs to be solved urgently. Summary of the invention

[0006] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides a cold spring chamber gas concentration detection device and detection method. The device performs quantitative separation of water vapor outside the cold spring chamber. The gas is collected and pressurized and then sent directly to a gas chromatograph for detection to obtain the volume fractions of various gases in the mixed gas. The concentrations of each component gas separated from the solution are obtained in combination with the water vapor quantitative separation data.

[0007] The technical solution adopted by the present invention is as follows: A gas concentration detection device for a cold spring cabin, comprising:

[0008] A separation component for separating water and gas from the solution in the cold spring cabin, the separation component comprising a multi-stage series-connected separation membrane;

[0009] A first flowmeter and a second flowmeter, respectively connected to the water production end and the gas production end of the separation component, for measuring the volume of the separated liquid and the volume of the gas;

[0010] A gas booster pump for boosting the separated gas;

[0011] An air storage tank connected to the gas booster pump for collecting and storing the boosted mixed gas;

[0012] A gas chromatograph connected to the air storage tank through a pipeline for detecting the volume fraction of each gas component in the mixed gas;

[0013] A vacuum pump connected to the separation component for evacuating the inside of the separation component before separation;

[0014] A plurality of solenoid valves and pressure reducing valves for controlling the on-off of the pipeline and adjusting the gas pressure;

[0015] A control module for calculating the concentration of the gas in the solution according to the flow data of the first flowmeter and the second flowmeter and the volume fraction data of the gas chromatograph.

[0016] In one embodiment, a movable piston is provided in the air storage tank, and a first limit switch and a second limit switch are respectively connected to both sides of the piston for detecting the position of the piston to control gas collection and evacuation.

[0017] In one embodiment, a nitrogen cylinder and a gas mixing tank are further included. The nitrogen cylinder is connected to the gas mixing tank through a second solenoid valve and a seventh solenoid valve for diluting or safely discharging the mixed gas.

[0018] In one embodiment, the separation component includes at least three stages of separation membranes; preferably, the pore size range of the separation membrane is 0.01 - 0.1 μm.

[0019] In one embodiment, the outlet pressure of the gas booster pump is set to 1 MPa, and the inlet pressure of the gas chromatograph is adjusted by a fourth pressure reducing valve.

[0020] On the other hand, the present invention also provides a method for detecting the gas concentration in a cold spring cabin, comprising the following steps:

[0021] Step S1: Perform a vacuum treatment on the separation component to make the internal pressure stable in a negative pressure state;

[0022] Step S2: Input the cold spring cabin solution into the separation component, separate water vapor through a multi-stage separation membrane, and simultaneously record the volume of the separated liquid and gas.

[0023] Step S3: Pressurize the separated gas to a set pressure by a gas booster pump and store it in the gas storage tank.

[0024] Step S4: Transport the mixed gas in the gas storage tank to a gas chromatograph to detect the volume fractions of each gas component.

[0025] Step S5: Calculate the concentration of each gas in the solution based on the liquid volume and gas volume recorded in Step S2 and in combination with the volume fraction data of the gas chromatograph.

[0026] In one embodiment, in Step S1, when the pressure change during the vacuum pumping process is less than 0.01 bar, it is regarded as stable.

[0027] In one embodiment, in Step S3, the initialization of the gas storage tank includes driving a movable piston to a preset position by gas pressure to evacuate the residual gas in the tank.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention has a reasonable structure and is easy to operate. It realizes efficient water-vapor separation through the cooperation of a multi-stage separation membrane and a vacuum pump, avoiding the cumbersome pretreatment of the traditional gas chromatography method and shortening the detection time. In addition, by combining the gas-liquid volume data (recorded by a flowmeter) after separation with the gas chromatograph volume fraction, the gas concentration in the solution is directly calculated, breaking through the limitation that the volume fraction cannot accurately map the solution concentration.

[0030] The present invention also has the following advantages:

[0031] (1) The gas storage tank of the present invention is internally provided with a movable piston and is connected with a limit switch to ensure that there is no residual interference in gas collection. The booster pump and pressure reducing valve accurately regulate the pressure, improving the detection consistency.

[0032] (2) The present invention has the functions of nitrogen dilution and safe discharge, and can be adapted to gas detection in deep-sea cold spring cabins and other sealed environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the basic architecture of the present invention.

[0034] Figure 2 It is a schematic diagram of the working principle of the present invention.

[0035] Figure 3 It is a schematic diagram of the composition structure of the present invention.

[0036] Figure 4 It is the flowchart of evacuating the separation membrane in the present invention.

[0037] Figure 5 It is the flowchart of initializing the gas storage tank in the present invention.

[0038] Figure 6 It is the flowchart of gas collection and pressurization of the gas storage tank in the present invention.

[0039] Figure 7 It is the flowchart of gas chromatography detection of the mixed gas in the present invention.

[0040] Figure 8 It is the schematic diagram of pipeline connection of the gas storage tank in the present invention.

[0041] Wherein:

[0042] 110, the first solenoid valve; 120, the second solenoid valve; 130, the third solenoid valve; 140, the fourth solenoid valve; 150, the fifth solenoid valve; 160, the sixth solenoid valve; 170, the seventh solenoid valve; 180, the eighth solenoid valve; 190, the ninth solenoid valve;

[0043] 210, the first pressure reducing valve; 220, the second pressure reducing valve; 230, the third pressure reducing valve; 240, the fourth pressure reducing valve;

[0044] 300, the filter;

[0045] 400, the separation component;

[0046] 510, the first flowmeter; 520, the second flowmeter;

[0047] 600, the vacuum pump;

[0048] 700, the nitrogen cylinder;

[0049] 800, the flow regulating valve;

[0050] 900, the gas booster pump;

[0051] 1000, the check valve;

[0052] 1100, the gas storage tank;

[0053] 1210, the first limit switch; 1220, the second limit switch;

[0054] 1300, the gas mixing tank;

[0055] 1400, the gas chromatograph. Specific embodiments

[0056] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. In the description of the present invention, it should be understood that 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. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the 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 on the present invention.

[0057] In addition, the terms "first" and "second" are only used for descriptive purposes 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 of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood 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 internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. 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.

[0059] In the present invention, unless otherwise clearly specified and limited, 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 indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature may be 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.

[0060] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can 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 can 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 only for the purpose of illustration and do not represent the only implementation.

[0061] As Figures 1 - 8 shown, a cold spring cabin gas concentration detection device of the present invention includes the following modules:

[0062] Water-vapor separation module:

[0063] The separation component 400, which is composed of three-stage series separation membranes (pore size 0.01 - 0.1 μm), is connected to the first solenoid valve 110 and the third solenoid valve 130, and is used to receive the cold spring cabin solution and perform water-vapor separation;

[0064] The vacuum pump 600 is connected to the separation component 400 through the third solenoid valve 130, and is used to pump vacuum to establish a negative pressure environment (pressure fluctuation ≤ 0.01 bar);

[0065] The filter 300 is arranged at the inlet end of the separation component 400, and the inlet pressure is adjusted by the first pressure reducing valve 210 to filter impurities in the solution;

[0066] The flow monitoring unit, the water production end of the separation component 400 is connected to the first flowmeter 510, and the gas production end is connected to the second flowmeter 520, and is used to record the volume of the separated liquid and gas in real time.

[0067] Gas collection and boosting module:

[0068] The gas storage tank 1100 is internally provided with a movable piston, and the first limit switch 1210 and the second limit switch 1220 are respectively installed on both sides, and are used to detect the piston position;

[0069] During initialization, the fourth solenoid valve 140, the fifth solenoid valve 150 and the eighth solenoid valve 180 are opened, and the gas booster pump 900 drives the piston to move until the second limit switch 1220 is triggered to evacuate the air in the tank;

[0070] When collecting gas, the fifth solenoid valve 150 and the eighth solenoid valve 180 are closed, the sixth solenoid valve 160 and the seventh solenoid valve 170 are opened, and the piston stops after the first limit switch 1210 is triggered, and the gas is boosted to 1 MPa;

[0071] The gas booster pump 900 controls the flow through the flow regulating valve 800 and delivers the boosted gas to the gas storage tank 1100 through the check valve 1000.

[0072] Dilution and Safe Discharge Module:

[0073] The nitrogen gas cylinder 700 is connected to the gas mixing tank 1300 through the second solenoid valve 120, the seventh solenoid valve 170, and the second pressure reducing valve 220 for diluting over-range gases or safe discharge.

[0074] The gas mixing tank 1300 is connected to the gas storage tank 1100 through the third pressure reducing valve 230 and the eighth solenoid valve 180 to achieve dilution or discharge of the mixed gas.

[0075] Detection and Analysis Module:

[0076] The gas chromatograph 1400 is connected to the gas storage tank 1100 through the ninth solenoid valve 190 and the fourth pressure reducing valve 240. The fourth pressure reducing valve 240 adjusts the gas pressure to 0.2 MPa for detection.

[0077] The control module calculates the concentration of the gas in the solution according to the formula based on the volume data of the first flowmeter 510 and the second flowmeter 520 and the volume fraction of the gas chromatograph 1400.

[0078] In other embodiments, the present invention also provides a method for detecting the gas concentration in the cold spring cabin, including the following processes:

[0079] As Figure 4 shown, evacuate the separation component:

[0080] Open the third solenoid valve 130 and the vacuum pump 600. After the pressure in the separation component 400 is stable (fluctuation < 0.01 bar), open the second solenoid valve 120, adjust the second pressure reducing valve 220 and the third pressure reducing valve 230, and start the safe discharge.

[0081] As Figure 5 shown, initialize the gas storage tank:

[0082] Open the first solenoid valve 110, the fourth solenoid valve 140, the fifth solenoid valve 150, and the eighth solenoid valve 180. Start the gas booster pump 900, adjust the flow regulating valve 800, and drive the piston until the second limit switch 1220 is triggered to evacuate the air in the tank.

[0083] As Figure 6 shown, gas collection and pressurization:

[0084] Close the fifth solenoid valve 150 and the eighth solenoid valve 180, open the sixth solenoid valve 160 and the seventh solenoid valve 170. The gas storage tank 1100 collects the separated gas. When the first limit switch 1210 is triggered, close the second solenoid valve 120 and the seventh solenoid valve 170, and pressurize to 1 MPa.

[0085] AsFigure 7 As shown, gas chromatography detection:

[0086] Turn off the gas booster pump 900, open the ninth solenoid valve 190, adjust the fourth pressure reducing valve 240 to 0.2 MPa, and the mixed gas enters the gas chromatograph 1400 to detect the volume fraction.

[0087] Finally, according to the recorded data parameters, calculate the concentrations of each gas in the solution according to the formula; if the detection exceeds the range, inject dilution gas through the nitrogen cylinder 700 and re-detect.

[0088] Exemplarily, taking methane gas as an example below, the calculation process of gas concentration will be specifically described. The volume fraction of methane obtained by gas chromatography detection The volume fraction of methane can be expressed as:

[0089]

[0090] The molar volume of gas V m is approximately 22.4 L / mol, and the concentration n of methane in the solution in the cold seep simulation chamber 甲烷 can be expressed as Equation 2

[0091]

[0092] From Equation 1, it can be obtained that:

[0093]

[0094] From Equation 2 and Equation 3, the concentration of methane in the solution can be finally obtained.

[0095]

[0096] Similarly, the other gas components in the mixed gas can also be obtained according to the above calculation method.

[0097] In summary, the present invention can achieve rapid and direct detection of gases in the solution of the cold seep cabin, and can directly give the concentration data of gases in the solution; a negative pressure is established inside the separation component 400 through the vacuum pump 600, and the characteristics of the microporous semi-permeable membrane of the separation component 400 are utilized to realize the separation of water and gas in the solution. Combining the flow data of the first flowmeter 510 at the water production end and the second flowmeter 520 at the gas production end, the water-gas separation ratio is obtained; the gas booster pump 900 collects the separated gas into the gas storage tank 1100 and pressurizes it. After adjusting the mixed gas to an appropriate pressure through the fourth pressure reducing valve 240, it is sent to the gas chromatograph for detection to obtain the volume fraction of each gas in the mixed gas. Combining the volume data of water and gas in the separated solution, the concentration data of each gas in the solution is calculated.

[0098] 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 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.

[0099] The above-described embodiments only express the implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on 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 deformations 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 gas concentration detection device for a cold spring cabin, characterized in that Comprising: A separation component for separating water vapor from the solution in the cold spring cabin, the separation component including a multi-stage series of separation membranes; A first flowmeter and a second flowmeter, respectively connected to the water production end and the gas production end of the separation component, for measuring the volume of the separated liquid and gas; A gas booster pump for boosting the separated gas; An air storage tank connected to the gas booster pump for collecting and storing the boosted mixed gas; A gas chromatograph connected to the air storage tank through a pipeline for detecting the volume fraction of each gas component in the mixed gas; A vacuum pump connected to the separation component for evacuating the inside of the separation component before separation; A plurality of solenoid valves and pressure reducing valves for controlling the on / off of the pipeline and adjusting the gas pressure; A control module for calculating the concentration of gas in the solution based on the flow data of the first flowmeter and the second flowmeter and the volume fraction data of the gas chromatograph.

2. The cold spring cabin gas concentration detection device according to claim 1, characterized in that A movable piston is provided in the air storage tank, and a first limit switch and a second limit switch are respectively connected to both sides of the piston for detecting the position of the piston to control gas collection and evacuation.

3. The cold spring cabin gas concentration detection device according to claim 1, characterized in that, It further includes a nitrogen cylinder and a gas mixing tank, and the nitrogen cylinder is connected to the gas mixing tank through a second solenoid valve and a seventh solenoid valve for diluting or safely discharging the mixed gas.

4. The cold spring cabin gas concentration detection device according to claim 1, characterized in that, The separation component includes at least three stages of separation membranes.

5. The cold spring cabin gas concentration detection device according to claim 4, characterized in that, The pore size range of the separation membrane is 0.01 - 0.1 μm.

6. The cold spring cabin gas concentration detection device according to claim 1, wherein The outlet pressure of the gas booster pump is set to 1 MPa, and the inlet pressure of the gas chromatograph is adjusted by a fourth pressure reducing valve.

7. A method for detecting gas concentration in a cold spring cabin, characterized in that, Including the following steps: Step S1: Perform a vacuum treatment on the separation component to make the internal pressure stable in a negative pressure state; Step S2: Input the cold spring cabin solution into the separation component, separate water vapor through the multi-stage separation membranes, and simultaneously record the volume of the separated liquid and gas; Step S3: Boost the separated gas to a set pressure by the gas booster pump and store it in the air storage tank; Step S4: Transport the mixed gas in the air storage tank to the gas chromatograph to detect the volume fraction of each gas component; Step S5: Calculate the concentration of each gas in the solution based on the liquid volume and gas volume recorded in Step S2 and the volume fraction data of the gas chromatograph.

8. The method for detecting the gas concentration in the cold spring cabin according to claim 7, wherein, In Step S1, when the pressure change during the vacuum treatment is less than 0.01 bar, it is regarded as stable.

9. The method for detecting the gas concentration in the cold spring cabin according to claim 7, wherein, In Step S3, the initialization of the air storage tank includes driving the movable piston to a preset position by gas pressure to evacuate the residual gas in the tank.

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