System and method for analyzing and detecting trace permanent impurity gas components in liquid and gas

Abstract

The invention discloses an analysis and detection system for trace permanent impurity gas components in liquid and gas and a detection method thereof, which are suitable for determining trace gas component impurities in liquid and trace gas component impurities in high-purity gas. The system is equipped with a pulse discharge helium ionization detector, a hydrogen flame ionization detector, a thermal conductivity detector and a headspace sampling and valve sampling system, adopts five valves, four columns and four channels, realizes effective separation of helium in a first channel and a first chromatographic column, and performs detection through a TCD detector. Effective separation of carbon monoxide, carbon dioxide and methane is realized in a third channel and a third chromatographic column, and detection is performed through an FID detector. The system is high in integration level, wide in application range, high in detection efficiency, strong in operability and accurate and reliable in detection result, and the detection level can reach 10 <-3 > mu mol / mol.

Description

Technical Field

[0001] The present invention relates to the field of analytical technology, and in particular to a system and method for analyzing and detecting trace permanent impurity gas components in liquid and gas. Background Art

[0002] At present, there is an increasing demand for the detection of trace gas impurity components in high-purity gas, liquid and other samples, such as in the field of fuel cell hydrogen, groundwater detection, and insulating oil detection. Existing detection methods often require multiple detection instruments to perform detection in sequence, which not only leads to high detection costs, but also complex operations and high time costs. The detection accuracy is insufficient, and many unknown impurities are still difficult to be effectively detected by existing technologies, which undoubtedly brings considerable challenges to the research and application of related fields.

[0003] At present, the country has clear requirements for the content of gas impurity components such as oxygen, argon, nitrogen, carbon monoxide, and carbon dioxide in pure hydrogen, high-purity hydrogen, ultra-pure hydrogen, and hydrogen used in proton exchange membrane fuel cell vehicles. There are many methods for detecting impurity gas components in hydrogen, usually gas chromatography is the main method, but due to the large number of gas components involved in the detection, multiple instruments are required to carry out the detection to complete the relevant work.

[0004] Prior art CN202211463375.2 discloses a gas chromatography system and method for detecting permanent gases in fuel cell hydrogen, the gas chromatography system comprising a first analysis channel, a second analysis channel and a carrier gas channel, so that hydrogen can achieve separation of CO, O2, Ar, N2, CH4 in the first and second chromatographic columns, separation of CO2 in the third chromatographic column, and separation of H2 in the fourth chromatographic column. However, this solution cannot achieve separation and calculation of total hydrocarbons.

[0005] In addition to the detection of hydrogen for fuel cells, there is also a need for impurity detection for other high-purity gases. However, the detection schemes in the prior art can often only be used for samples from a specific source, lacking flexibility, that is, a set of detection systems can only be used for samples from a specific source. Therefore, how to achieve the detection of multi-component gas impurities in samples from different sources through the same set of detection methods is also a problem that needs to be solved at present. The standard detection methods for liquids (groundwater, insulating oil, etc.) in the prior art include DZ / T0064.74-2021, GB / T 17623-2017, etc., in which helium (He), hydrogen (H2), oxygen (O2), nitrogen (N2), argon (Ar), methane (CH4), carbon monoxide (CO), carbon dioxide (CO2) and other gases dissolved or escaped in liquids (groundwater, insulating oil, etc.) are measured. The prior art also requires multiple sets of gas chromatographs to be used together, which is complicated to operate, time-consuming, and the detection sensitivity and precision are difficult to meet the requirements. Summary of the invention

[0006] The present invention aims to overcome at least one defect of the above-mentioned prior art and provides a system for analyzing and detecting trace permanent impurity gas components in liquids and gases and a detection method thereof. By integrating multiple detectors and injection systems, the purpose of expanding the detection objects and improving the detection efficiency and detection accuracy is achieved, and multiple trace permanent impurity gas components can be detected simultaneously.

[0007] Specifically, the present invention provides a gas component analysis and detection system for trace permanent impurities in liquid and gas, comprising a first valve, a first quantitative ring, a second quantitative ring, a third quantitative ring, and a fourth quantitative ring connected in series, wherein the first quantitative ring is connected to the inlet of the sample to be tested through the first valve, and the injection port supports two modes of head space injection and valve injection, wherein the gas in the liquid is injected through the head space; the high-purity gas is injected through the valve; and further comprising: a first channel: comprising a first carrier gas, a first backwash column, a second valve, a first pre-column, and a first chromatographic column connected in sequence; a first separation channel: comprising a second carrier gas, a first front flush column, a first chromatographic column, and a HID detector; a first exhaust channel: comprising a first carrier gas, a first backwash column, a first pre-column, a first exhaust valve, and a first purge gas outlet connected through a pipeline; a second channel: comprising a third carrier gas, a second backwash column, a third valve, a second pre-column, and a second chromatographic column; a second separation channel: comprising a fourth carrier gas, a second front flush column, a second chromatographic column, and a TCD detector; a second exhaust channel: comprising a third carrier gas, a second backwash column, a second pre-column, a second exhaust valve, and a second The purge gas outlet; the third channel: including the fifth carrier gas, the third front flushing column, the fourth valve, the third chromatographic column and the FID detector; the fourth channel, including the sixth carrier gas, the third back flushing column, the fifth valve, the third pre-column and the fourth chromatographic column; the third separation channel: including the seventh carrier gas, the fourth front flushing column, the fourth chromatographic column and the FID detector; the third exhaust channel, including the sixth carrier gas, the third back flushing column, the third pre-column, the third exhaust valve and the third purge gas outlet; the sample to be tested in the first quantitative loop is transmitted to the first chromatographic column through the first channel; and then the HID detector of the first separation channel is used to detect H2, Ar, O2 and N2; the sample to be tested in the second quantitative loop is transmitted to the second chromatographic column through the second channel; and then the TCD detector of the second separation channel is used to detect He; the sample to be tested in the third quantitative loop is transmitted to the third chromatographic column for separation through the third channel, and then the total hydrocarbons are detected through the FID detector; the sample to be tested in the fourth quantitative loop is transmitted to the fourth chromatographic column for separation through the fourth channel, and then the CO, CO2 and CH4 are detected through the FID detector of the third separation channel.

[0008] The present invention designs four channels for separating gases of different properties, and the three detectors equipped can achieve high sensitivity and good selectivity for the gas components to be tested, and the detection effect of organic gas components, inorganic gases and some non-polar gases is significantly improved. The present invention is equipped with a headspace sampling system and a valve sampling system, which can be used for the detection of gases in groundwater and insulating oil, and can also be used for the detection of trace gas components in high-purity gases. It has a wide range of applications and high detection efficiency. The entire sampling and detection process is short, and it has higher precision and lower detection limit, which greatly improves the detection efficiency.

[0009] The present invention uses a multidimensional gas chromatography with a pulse discharge helium ionization detector, a thermal conductivity detector, a hydrogen flame ionization detector and a methane converter multi-channel configuration to simultaneously determine the contents of various impurity gas components such as total hydrocarbons, methane, carbon monoxide, carbon dioxide, helium, argon, oxygen, nitrogen, etc. in the gas in the liquid or high-purity gas. The gas sample enters the quantitative loop of each channel through the injection port, and the sample in the quantitative loop is introduced into 4 different detection channels through valve switching. After pre-column separation, the target component is brought into the chromatographic column for further separation, and then detected in the corresponding detector. After separation and determination, the external standard method is used for quantification, and the detection limits of the eight gas components are: He: 4.65μmol / mol; N2: 3.7×10 -3 μmol / mol、Ar:1.3×10 -3 μmol / mol, CO:3.7×10 -2 μmol / mol, CO2:8.7×10 -2 μmol / mol, total hydrocarbons: 3.1×10 -2 μmol / mol, CH4:3.3×10 -2 μmol / mol, O2:2.1×10 -3 μmol / mol.

[0010] The gases of the first carrier gas and the second carrier gas are He; the gases of the third carrier gas, the fourth carrier gas and the fifth carrier gas are H2; and the gases of the sixth carrier gas and the seventh carrier gas are N2.

[0011] Furthermore, a particle trap is provided between the first chromatographic column and the HID detector; a TCD isothermal furnace is provided between the second chromatographic column and the TCD detector; and a methanator is provided between the fourth chromatographic column and the FID detector.

[0012] Furthermore, the first chromatographic column, the second chromatographic column and the fourth chromatographic column are molecular sieve columns, and the third chromatographic column is a capillary column.

[0013] Furthermore, a first exhaust valve is provided between the first pre-column and the first purge gas outlet; a second exhaust valve is provided between the second pre-column and the second purge gas outlet; and a third exhaust valve is provided between the third pre-column and the third purge gas outlet.

[0014] Preferably, the injection port comprises two types of injection ports, a head space injection port and a gas valve injection port.

[0015] The present invention also provides a method for analyzing and detecting trace permanent impurity gas components in liquid and gas, comprising the following steps: S1: after the liquid (groundwater, insulating oil, etc.) sample is collected by a headspace injection bottle, it enters the GC system through the headspace injection mode; the gas sample directly enters the GC detection system through the valve injection mode;

[0016] S2: Open the first valve, and the sample to be tested enters and fills the first quantitative ring, the second quantitative ring, the third quantitative ring, and the fourth quantitative ring;

[0017] S3: Open the second valve, and the first carrier gas introduces the gas sample in the first quantitative loop into the first pre-column, wherein the heavy components remain in the first pre-column, and the light components H2, Ar, O2, and N2 are blown to the first chromatographic column;

[0018] S4: the second valve is closed, the first carrier gas back-flushes the first pre-column, and the heavy components are discharged from the first exhaust valve and the first purge gas outlet; the second carrier gas carries the light components H2, Ar, O2, and N2 into the first chromatographic column for separation, and is detected by HID;

[0019] S5: Open the third valve, and the third carrier gas introduces the gas sample in the second quantitative loop into the second pre-column, wherein the heavy component remains in the second pre-column, and the light component He is blown to the second chromatographic column;

[0020] S6: Close the third valve, back-flush the second pre-column with the second carrier gas, and discharge the heavy component from the second purge gas outlet; the fourth carrier gas carries the light component He into the second chromatographic column for separation, and then detects by TCD;

[0021] S7: Open the fourth valve, and the fifth carrier gas introduces the gas sample in the third quantitative loop into the third chromatographic column;

[0022] S8: close the fourth valve, and the fifth carrier gas carries the total hydrocarbons into the third chromatographic column for separation, and then is detected by FID;

[0023] S9: Open the fifth valve, and the sixth carrier gas introduces the gas sample in the fourth quantitative loop into the third pre-column, wherein the heavy components remain in the third pre-column, and the light components CO, CO2, and CH4 are blown to the fourth chromatographic column;

[0024] S10: Close the fifth valve, and use the sixth carrier gas to backflush the third pre-column, and discharge the heavy components from the third purge gas outlet; the seventh carrier gas carries the light components CO, CO2, and CH4 into the fourth chromatographic column for separation, and then detects by FID.

[0025] Preferably, when the sample to be tested is gas in liquid, such as gas in groundwater, insulating oil, etc., the injection method is: the sample is placed in a headspace bottle, and by pressurizing the sample in the headspace bottle, the gas in the liquid is introduced into the GC system along with the carrier gas or directly enters the GC system by the pressure difference in the bottle;

[0026] Preferably, when the sample to be tested is a high-purity gas, such as hydrogen, it can be directly introduced into the GC system from a gas cylinder through a valve and then analyzed and tested.

[0027] Furthermore, the time points of the analysis and detection are:

[0028] time valve switch 0.01 First Valve open 0.1 Second valve open 0.11 The third valve open 0.12 The fourth valve open 0.13 Fifth valve open 0.5 Second valve close 0.99 The fourth valve close 1.1 First Valve close 1.5 The third valve close 2.1 Fifth valve close .

[0029] Furthermore, the pressure during the detection process is set to:

[0030]

[0031]

[0032] Furthermore, the analytical detection method of the present invention also includes a step of cleaning or flow flushing before sampling to remove oxygen in the system before step S1: using a pressure regulator with 1 μmol / mol calibration gas to clean more than 18 times, or flushing the sampling part of the system at a flow rate of 50 to 60 mL / min for 30 minutes until the oxygen response is stable.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention discloses a high-precision analysis and detection system for trace permanent impurity gas components in liquids and gases and a corresponding detection method. The system realizes comprehensive, efficient and accurate detection of trace gas component impurities in liquids and gases by innovatively integrating a pulse discharge helium ionization detector, a hydrogen flame ionization detector and a thermal conductivity detector, and cooperating with a headspace sampling and valve sampling system. Specifically, the design concept of the trace permanent impurity gas component analysis and detection system in liquids and gases disclosed by the present invention is based on the principle of complementary advantages of multiple detection technologies. Among them, the pulse discharge helium ionization detector can effectively capture extremely low concentrations of impurity gas components in liquid samples with its high sensitivity and good selectivity; the hydrogen flame ionization detector further enhances the detection capability of the system with its excellent response performance to organic gas components; at the same time, the introduction of the thermal conductivity detector significantly improves the detection effect of the system for inorganic gases and some non-polar gases. In addition, the system of the present invention is also specially equipped with a headspace injection system and a valve injection system. The combined use of these two injection methods not only greatly improves the flexibility and efficiency of sample processing and expands the application range of the system, but also can effectively reduce the contamination and loss of samples during the injection process, thereby ensuring the accuracy and reliability of the test results.

[0035] In summary, the trace permanent impurity gas component analysis detection system and detection method in liquids and gases provided by the present invention, through scientific technology integration and innovative design ideas, successfully solves the limitations of traditional detection methods in terms of sensitivity, selectivity and sample processing efficiency, and provides strong technical support for research and application in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the working principle of the gas component analysis and detection system for trace permanent impurities in liquids and gases of the present invention.

[0037] Figure 2 The invention discloses a gas chromatogram for detecting impurity components in hydrogen by using the gas component analysis detection system and detection method for trace permanent impurities in liquid and gas of the present invention.

[0038] Figure 3 This is the gas chromatogram of impurity components detected by FID detector.

[0039] Figure 4 Gas chromatogram of impurity components detected by TCD detector

[0040] Figure 5 Gas chromatogram of impurity components detected by HID detector DETAILED DESCRIPTION

[0041] The drawings in the embodiments provide a more detailed description of the technical solutions in the embodiments of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0042] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0044] Example

[0045] This embodiment provides a system for analyzing and detecting trace permanent impurity gas components in liquids and gases. Figure 1As shown, it includes a first valve 1, a first quantitative ring 2, a second quantitative ring 3, a third quantitative ring 4, and a fourth quantitative ring 5, which are connected in series. The first quantitative ring 2 is connected to the sample inlet to be tested through the first valve 1; it also includes: a first channel: including a first carrier gas He, a first backwash column 6, a second valve 7, a first pre-column 8, and a first chromatographic column 9 that are connected in sequence; a first separation channel: including a second carrier gas He, a first front flush column 10, a first chromatographic column 9, a particle trap 11, and a HID detector; a first exhaust channel: including a first carrier gas He, a first backwash column 6, a first pre-column 8, a first exhaust valve 12, and a first purge gas outlet 13 connected by a pipeline; a second channel: including a third carrier gas H2, a second backwash column 14, a third valve 15, a second pre-column 16, and a second chromatographic column 17; a second separation channel: including a fourth carrier gas H2, a second front flush column 18, a second Chromatographic column 17, TCD isothermal furnace 19, TCD detector 20; second exhaust channel, including the third carrier gas H2, the second backwash column 14, the second pre-column 16, the second exhaust valve 21, and the second purge gas outlet 23 connected by pipelines; third channel: including the fifth carrier gas H2, the third pre-flush column 24, the fourth valve 25, the third chromatographic column 26 and the FID detector; the fourth channel, including the sixth carrier gas N2, the third backwash column 27, the fifth valve 28, the third pre-column 29, and the fourth chromatographic column 30; the third separation channel: including the seventh carrier gas N2, the fourth pre-flush column 31, the fourth chromatographic column 30, the methanator 32, and the FID detector; the third exhaust channel, including the sixth carrier gas N2, the third backwash column 27, the third pre-column 29, the third exhaust valve 33, and the third purge gas outlet 34; a methanator hydrogen supply point 35 is also provided below the methanator 32. The sample to be tested in the first quantitative loop 2 is transmitted to the first chromatographic column 9 through the first channel; and then the HID detector of the first separation channel is used to detect H2, Ar, O2, and N2; the sample to be tested in the second quantitative loop 3 is transmitted to the second chromatographic column 17 through the second channel; and then the TCD detector 20 of the second separation channel is used to detect He; the sample to be tested in the third quantitative loop 4 is transmitted to the third chromatographic column 26 through the third channel for separation, and then the total hydrocarbons are detected through the FID detector; the sample to be tested in the fourth quantitative loop 5 is transmitted to the fourth chromatographic column 30 through the fourth channel for separation, and then the FID detector of the third separation channel is used to detect CO, CO2, and CH4.

[0046] The first and second carrier gases are He, the third, fourth and fifth carrier gases are H2, and the sixth and seventh carrier gases are N2. The first chromatographic column 9, the second chromatographic column 17 and the fourth chromatographic column 30 are molecular sieve columns, and the third chromatographic column 26 is a capillary column.

[0047] Channel 1: This channel is used for the analysis of inert gases.

[0048] The sample is introduced into the first pre-column 8 through the valve of the injection / backwash column. After H2, Ar, O2 and N2 are eluted to the molecular sieve column, the first pre-column 8 is backwashed and all the heavier components are discharged from the first purge gas outlet 13. The first chromatographic column 9 is a molecular sieve column, which separates H2, Ar, O2 and N2 in an isothermal furnace. Detection is performed by a helium ionizer.

[0049] Channel 2: This channel is used for the analysis of helium.

[0050] The sample is introduced into the second pre-column 16 by the injection / backwash valve. After He and H2 are eluted into the second chromatographic column 17, i.e., the molecular sieve column, the first pre-column 8 is backwashed, and all heavier components are discharged from the second purge gas outlet 23. The molecular sieve column separates He and H2 in an isothermal furnace. Detection is performed by a thermal conductivity detector (TCD).

[0051] Channel 3: This channel is used to analyze the total hydrocarbon content (THC).

[0052] The sample is introduced directly into the third chromatographic column 26, i.e., the capillary column, by the gas injection valve. The hydrocarbons are not retained and pass through the capillary column as a group, forming a composite peak, producing the result of total hydrocarbons, i.e., total hydrocarbons. Detection is by a flame ionization detector (FID).

[0053] Channel 4: This channel is used for the analysis of trace CO, methane and CO2.

[0054] The sample enters the third pre-column 29 through the gas sampling / backwash column valve. After eluting carbon dioxide (CO2) to the fourth chromatographic column 30, the valve is switched to backwash the remaining components to the third exhaust port. Carbon monoxide (CO), carbon dioxide (CO2) and methane are separated on the fourth chromatographic column 30 and converted into methane in the methanator 32. Detection is performed by a flame ionization detector (FID).

[0055] One implementation method of this embodiment is the detection of high-purity hydrogen. The hydrogen is stored in a gas cylinder. The gas in the gas cylinder enters the GC detection system through a valve, and enters different detection channels through the switches of various valves in the instrument. After different separation methods, the target object is detected in the detector.

[0056] The gas collection method in the liquid (groundwater, insulating oil, etc.) is the drainage gas collection method or the vacuum degassing method, and the collected gas enters the GC system through the headspace injection method. The air intake in the existing groundwater detection standard is only 100uL, and it is a manual injection. This process will produce a more obvious error. In addition, the detection requires multiple injections, and the chromatographic column and operating conditions required for each injection are different. The whole process takes a long time, and its environmental changes and human operation errors will cause the result to be offset. The present invention provides positive pressure in the headspace bottle by headspace injection, and then the gas enters the quantitative loop of the headspace injector, and then enters the gas chromatograph with the carrier gas. In addition, the gas in the liquid can also directly enter the chromatogram according to the pressure difference in the headspace bottle. The injection port valve in this experimental instrument opens at 0.01min and switches at 0.1min. At this time, the gas sample has filled the 4 quantitative loops in the 4 channels, and the volume of each quantitative loop is 0.5mL. In this experiment, the volume of the headspace bottle is 20mL, of which the gas accounts for about 2 / 3. Therefore, the gas volume can meet the requirements. As long as the injection rate is controlled, each quantitative loop in the detector can be filled within the specified time. Secondly, more gas can be obtained by selecting a larger headspace bottle.

[0057] The present invention selects the headspace sampling method for the detection of gas in liquid, reduces human error, increases the injection volume, reduces the uncertainty range, and improves the accuracy of the result. Secondly, through one-time injection, multi-channel, and multi-detector simultaneous determination, the error caused by time is reduced, time is saved, and rapid detection is achieved. Furthermore, each detection channel realizes accurate separation of the target substance by setting a pre-column, reduces impurity interference, and the chromatographic peaks are well separated without impurity peaks.

[0058] Pressure and flow

[0059] Flushing column Pressure(kPa) First backwash column 6 340 Second backwash column 14 413 The third backwash column 27 300 First pre-wash column 10 160 Second front flushing column 18 293 The third front flushing column 24 160 Fourth front flushing column 31 210

[0060] flow:

[0061]

[0062] Testing process

[0063] Time (min) valve switch 0.01 First valve 1 open 0.1 Second valve 7 open 0.11 The third valve 15 open 0.12 Fourth valve 25 open 0.13 Fifth valve 28 open 0.5 Second valve 7 close 0.99 Fourth valve 25 close 1.1 First valve 1 close 1.5 The third valve 15 close 2.1 Fifth valve 28 close

[0064] 0.0~0.01min: The instrument is ready to start, the carrier gases have started running, and the sample gas has not yet entered.

[0065] 0.01min: The first valve 1 opens and gas enters.

[0066] 0.01~0.1min: The gas fills the first quantitative loop 2, the second quantitative loop 3, the third quantitative loop 4 and the fourth quantitative loop 5, and the excess gas is discharged from the outlet 36 at the end of the fourth quantitative loop 5. This phenomenon can be observed at the gas outlet. Bubbles in the water 0.1min: The second valve 7 is opened, and the He at the first backwash column 6 introduces the gas sample in the quantitative loop into the first pre-column 8, wherein the heavy components remain in the pre-column, and the light components H2, Ar, O2, and N2 are blown to the first chromatographic column 9.

[0067] 0.5min: The second valve 7 is closed, and the He at the first backwash column 6 back-flushes the pre-column, and the heavy components are discharged from the first purge gas outlet 13; the He at the first pre-flush column 10 carries the light components H2, Ar, O2, and N2 into the first chromatographic column 9 for separation, and then detected by HID.

[0068] 0.11min: The third valve 15 is opened, and the H2 at the second backwash column 14 introduces the gas sample in the quantitative loop into the second pre-column 16, wherein the heavy components remain in the pre-column and the light component He is blown to the second chromatographic column 17.

[0069] 1.5min: The third valve 15 is closed, and the H2 at the second backwash column 14 back-flushes the pre-column, and the heavy components are discharged from the second purge gas outlet 23; the H2 at the second pre-flush column 18 carries the light component He into the second chromatographic column 17 for separation, and then detected by TCD.

[0070] 0.12min: The fourth valve 25 opens, and the H2 at the third front flushing column 24 introduces the gas sample in the quantitative loop into the third chromatographic column 26

[0071] 0.99min: The fourth valve 25 is closed, and the H2 at the third pre-flushing column 24 carries hydrocarbons into the third chromatographic column 26 for separation and then detected by FID. This channel does not need to pass through the pre-column, and the valve is closed for quantitative determination of the gas sample.

[0072] 0.13min: The fifth valve 28 is opened, and the N2 at the third backwash column 27 introduces the gas sample in the quantitative loop into the pre-column 1, wherein the heavy components remain in the pre-column, and the light components CO, CO2, and CH4 are blown to the fourth chromatographic column 30.

[0073] 2.1min: The fifth valve 28 is closed, and the N2 at the third backwash column 27 back-flushes the pre-column, and the heavy components are discharged from the third purge gas outlet 34; the N2 at the fourth pre-flush column 31 carries the light components CO, CO2, and CH4 into the fourth chromatographic column 30 for separation, and then detected by FID.

[0074] 1.1min: The first valve 1 is closed, and the gas injection ends. At this time, the sample in the quantitative loop has been introduced into the column.

[0075] The different opening and closing times of the valves are different from the time it takes for the material components to pass through the pre-column. According to different detection indicators, the pre-column configuration used to intercept the heavy components is also different.

[0076] Analytical control test:

[0077] Detection Limit:

[0078] LDL = ((3*detection substance concentration*noise) / peak area)*half peak width*60;

[0079] The detection diagram of trace impurity gas in hydrogen in this embodiment is shown in FIG. Figures 2 to 5 The detection limit results are shown in Table 1 below:

[0080] Table 1 Test of detection limits of impurity components in fuel hydrogen

[0081]

[0082]

[0083] Repeatability

[0084] RSD% = A / S*100;

[0085] The detection results of trace gases in hydrogen in this embodiment are shown in Table 2.

[0086] Table 2 Inspection of impurity content in fuel hydrogen

[0087]

[0088] The above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit it. Although the present invention is described in detail with reference to the above preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention. Those skilled in the art may also make other changes within the spirit of the present invention and apply them to the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should be included in the scope of protection claimed by the present invention.

Claims

1. A system for analyzing and detecting trace permanent impurity gas components in liquids and gases, characterized in that: The invention comprises a first valve (1), a first quantitative ring (2), a second quantitative ring (3), a third quantitative ring (4), and a fourth quantitative ring (5) which are connected in series, wherein the first quantitative ring (2) is connected to the inlet of the sample to be tested via the first valve (1), and the injection port supports two modes of head space injection and valve injection, wherein the gas in the liquid is injected via the head space; and the gas is injected via the valve; and further comprises: The first channel comprises a first carrier gas, a first backwash column (6), a second valve (7), a first pre-column (8), and a first chromatographic column (9) which are connected in sequence; The first separation channel comprises a second carrier gas, a first front flushing column (10), a first chromatographic column (9), and a HID detector; A first exhaust passage, comprising a first carrier gas, a first backwash column (6), a first pre-column (8), a first exhaust valve (12) and a first purge gas outlet (13) connected by pipelines; The second channel comprises a third carrier gas, a second backwash column (14), a third valve (15), a second pre-column (16), and a second chromatographic column (17); The second separation channel comprises a fourth carrier gas, a second front flushing column (18), a second chromatographic column (17) and a TCD detector (20); A second exhaust passage, comprising a third carrier gas, a second backwash column (14), a second pre-column (16), a second exhaust valve (21) and a second purge gas outlet (23) connected by pipelines; The third channel comprises a fifth carrier gas, a third front flushing column (24), a fourth valve (25), a third chromatographic column (26) and a FID detector; a fourth channel, comprising a sixth carrier gas, a third backwash column (27), a fifth valve (28), a third pre-column (29), and a fourth chromatographic column (30); The third separation channel comprises a seventh carrier gas, a fourth front flushing column (31), a fourth chromatographic column (30) and a FID detector; A third exhaust passage, comprising a sixth carrier gas, a third backwash column (27), a third pre-column (29), a third exhaust valve (33) and a third purge gas outlet (34); The sample to be tested in the first quantitative loop (2) is transmitted to the first chromatographic column (9) through the first channel; and then the HID detector of the first separation channel is used to detect H2, Ar, O2, and N2; The sample to be tested in the second quantitative loop (3) is transmitted to the second chromatographic column (17) through the second channel; and then He is detected through the TCD detector (20) of the second separation channel; The sample to be tested in the third quantitative loop (4) is transmitted to the third chromatographic column (26) through the third channel for separation, and then the total hydrocarbons are detected by the FID detector; The sample to be tested in the fourth quantitative loop (5) is transmitted to the fourth chromatographic column (30) through the fourth channel for separation, and then the FID detector of the third separation channel is used to detect CO, CO2, and CH4.

2. The gas component analysis and detection system for trace permanent impurities in liquids and gases according to claim 1 is characterized in that: The gases of the first carrier gas and the second carrier gas are He; the gases of the third carrier gas, the fourth carrier gas and the fifth carrier gas are H2; and the gases of the sixth carrier gas and the seventh carrier gas are N2.

3. The system for analyzing and detecting trace permanent impurities in liquids and gases according to claim 1, characterized in that: A particle trap (11) is also provided between the first chromatographic column (9) and the HID detector; a TCD isothermal furnace (19) is provided between the second chromatographic column (17) and the TCD detector (20); and a methanator (32) is also provided between the fourth chromatographic column (30) and the FID detector.

4. The system for analyzing and detecting trace permanent impurities in liquids and gases according to claim 1, characterized in that: The first chromatographic column (9), the second chromatographic column (17) and the fourth chromatographic column (30) are molecular sieve columns, and the third chromatographic column (26) is a capillary column.

5. The system for analyzing and detecting trace permanent impurities in liquid and gas according to any one of claims 1 to 4, characterized in that: A first exhaust valve (12) is provided between the first pre-column (8) and the first purge gas outlet (13); a second exhaust valve (21) is provided between the second pre-column (16) and the second purge gas outlet (23); and a third exhaust valve (33) is provided between the third pre-column (29) and the third purge gas outlet (34).

6. A method for analyzing and detecting trace permanent impurity gas components in liquid and gas, comprising the system for analyzing and detecting trace permanent impurity gas components in liquid and gas according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: The gas in the liquid (groundwater, insulating oil, etc.) is collected by drainage gas collection method or vacuum degassing method. The collected gas enters the GC system through headspace injection method; the gas directly enters the GC detection system through valve injection method; S2: opening the first valve (1), allowing the sample to be tested to enter and fill the first quantitative ring (2), the second quantitative ring (3), the third quantitative ring (4), and the fourth quantitative ring (5); S3: Open the second valve (7), and the first carrier gas introduces the gas sample in the first quantitative loop (2) into the first pre-column (8), wherein the heavy components remain in the first pre-column (8), and the light components H2, Ar, O2, and N2 are blown to the first chromatographic column (9); S4: the second valve (7) is closed, the first carrier gas back-flushes the first pre-column (8), and the heavy components are discharged from the first exhaust valve (12) and the first purge gas outlet (13); the second carrier gas carries the light components H2, Ar, O2, and N2 into the first chromatographic column (9) for separation, and is detected by HID; S5: Open the third valve (15), and the third carrier gas introduces the gas sample in the second quantitative loop (3) into the second pre-column (16), wherein the heavy component remains in the second pre-column (16), and the light component He is blown to the second chromatographic column (17); S6: close the third valve (15), back-flush the second pre-column (16) with the second carrier gas, and discharge the heavy component substances from the second purge gas outlet (23); the fourth carrier gas carries the light component substances He into the second chromatographic column (17) for separation, and then detects by TCD; S7: Open the fourth valve (25), and the fifth carrier gas introduces the gas sample in the third quantitative loop (4) into the third chromatographic column (26); S8: the fourth valve (25) is closed, and the fifth carrier gas carries the total hydrocarbons into the third chromatographic column (26) for separation, and then is detected by FID; S9: Open the fifth valve (28), and the sixth carrier gas introduces the gas sample in the fourth quantitative loop (5) into the third pre-column (29), wherein the heavy components remain in the third pre-column (29), and the light components CO, CO2, and CH4 are blown to the fourth chromatographic column (30); S10: Close the fifth valve (28), back-flush the third pre-column (29) with the sixth carrier gas, and discharge the heavy component substances from the third purge gas outlet (34); the seventh carrier gas carries the light component substances CO, CO2, CH4 into the fourth chromatographic column (30) for separation, and then detects by FID.

7. The method for analyzing and detecting trace permanent impurity gas components in liquid and gas according to claim 6, characterized in that: The sample to be tested is a high-purity gas or a gas in a liquid. The gas in the liquid is sampled via the head space, and the gas is sampled via a valve.

8. The method for analyzing and detecting trace permanent impurity gas components in liquid and gas according to claim 6, characterized in that: The time points of the analysis and detection are: 。 9. The method for analyzing and detecting trace permanent impurity gas components in liquid and gas according to claim 6, characterized in that: The pressure setting during the detection process is:

10. The method for analyzing and detecting trace permanent impurity gas components in liquid and gas according to claim 6, characterized in that: The method also includes the step of cleaning or flow flushing before sampling to remove oxygen from the system before step S1: cleaning the pressure regulator with 1ppm calibration gas for more than 18 times, or flushing the sampling part of the system at a flow rate of 50-60ml / min for 30 minutes until the oxygen response is stable.

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