CN109856302B - Gas detection device for benzene series and operation method thereof - Google Patents

Abstract

The invention provides a gas detection device for benzene series, comprising a box body, the box body is provided with a gas sampling unit, and a gas separation unit, a detection unit, a data acquisition and processing unit, a gas separation unit, a detection unit, a data acquisition and processing unit, Control unit and carrier gas unit; the gas separation unit is arranged in an independent separation box. The gas separation unit includes a ten-way valve disposed inside the separation tank. In addition, the present invention also provides an operating method of the above-mentioned gas detection device for benzene-based compounds. The specific combination of chromatographic columns used in the gas detection device of the present invention, in conjunction with the ten-way valve with a special structure and connection relationship of the present invention, is especially suitable for the detection of benzene series in the atmosphere, which can continue without stopping the machine. Detection and cleaning can be repeated in a short period of time, avoiding systematic errors caused by external state changes, and the detection results are more reliable and accurate.

Description

A kind of gas detection device for benzene series and its operation method

technical field

This application declares that it claims the priority of the Chinese prior patent application with the application number 2018100419954 filed on January 17, 2018.

The invention relates to gas detection and analysis technology in the field of environmental protection, in particular to a detection device that can be used to detect gas components, in particular to a gas detection device for benzene series compounds and an operation method thereof.

Background technique

The field of environmental protection often needs to detect and analyze various gases, usually using a gas chromatograph. A gas chromatograph is a device that analyzes and detects mixed samples, and usually includes a gas path system, a sample injection system, a separation system, a circuit control system, a detection system, and a data acquisition and processing system. However, the existing gas chromatographs are generally installed in the laboratory, and the overall volume is very large. Complex airflow pipes and various power supply and control cables need to be connected between each system. The connection reliability of the entire device is very unstable. , the calibration needs to be re-checked if there is a slight change, basically there is no possibility that it can be easily carried.

CN 106841483 A discloses a chromatographic sample introduction and separation device, which is used in combination with an eight-port valve and a ten-port valve to improve analysis efficiency. However, the two sets of valves used only use half of the gas path for half the time, and the two sets of gas paths are not related to each other. The result is that the difference between the two sets of gas circuits can easily lead to systematic errors. For example, there must be volume differences between the two quantitative tubes, so there are unavoidable systematic errors. In addition, more gas pipelines require a large number of connecting pipelines. The more pipelines, the greater the error caused by the volume of the gas pipeline, and the greater the effect of the pipeline material on the adsorption of the components in the gas. In addition, the more pipes there are, the more likely the joints are to have connection failures, the time for calibration and troubleshooting will greatly increase, and the reliability of the system will deteriorate. The use of two sets of valves brings the problem of synchronization, the control conversion of the system is complicated, and the volume occupied by the two sets of valves is also larger, which is difficult to be used for portable emergency sampling and analysis.

CN 104374860 A discloses a portable gas analyzer, which adopts a single ten-way valve and two chromatographic columns to separate and analyze the gas. However, the introduction of the overall framework of the portable gas analyzer in the prior art is very simple, only the description includes the box body, and the box is provided with an automatic sampling and sampling mechanism, a sample gas separation mechanism and a chromatographic detection mechanism, and the automatic sampling and sampling mechanism includes ten channels. Valve, sampling ring, mixed gas separation mechanism mainly includes coarse separation chromatographic column, subdivision chromatographic column and auxiliary pipeline and insulation cotton, mixed gas detection mechanism mainly includes fuel cell and auxiliary pipeline. As for the gas delivery, equipment calibration, equipment control, etc., there is no description, and those skilled in the art cannot imagine the overall structure of the portable gas analyzer in the prior art. In addition, in this prior art, two chromatographic columns are used in combination to separate gases, and the influence of impurities is removed by connecting them in series. When in use, the two chromatographic columns are kept in continuous series, one state is sampling and cleaning pipeline, and one state is Injection analysis. However, the dual chromatographic columns of the prior art are continuously used in series, and the target segment species can only be selectively highlighted according to the two columns, thereby ignoring the remaining segments. However, the prior art cannot remove interfering substances and cannot remove trace gases in trace gases. The peak shapes of different components are widened, the peak shape subdivision of the species in the target segment is not enough, and the accuracy of the analysis results needs to be improved.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a gas detection device for benzene series and an operation method thereof, so as to reduce or avoid the aforementioned problems.

Specifically, the present invention provides a gas detection device for benzene series, which can effectively reduce system errors, improve system reliability and detection accuracy, and can be more practical and portable.

In order to solve the above technical problems, the present invention proposes a gas detection device for benzene series, including a box body, the box body is provided with a gas sampling unit, and the interior of the box body is provided with a gas separation unit, a detection unit, data acquisition and processing unit, control unit and carrier gas unit; wherein, the gas separation unit is arranged in an independent separation box, and the separation box is provided with three air inlet pipes and three exhaust gas pipes communicating with the inside thereof The three air inlet pipes are respectively the first air inlet pipe and the second air inlet pipe that communicate with the carrier gas unit, and the third air inlet pipe that communicates with the gas sampling unit; the three exhaust pipes are respectively A first exhaust pipe and a second exhaust pipe for venting, and a third exhaust pipe communicating with the detection unit, a sampling pump is arranged in the second exhaust pipe; the gas separation unit includes a set of A ten-way valve inside the separation box, the ten-way valve has first to tenth connection ports numbered in sequence according to the adjacent positions; wherein, the first connection port and the eighth connection port are provided with a first chromatography The pipeline of the column is communicated; the second connection port is communicated with the third exhaust pipe, and the third exhaust pipe is provided with a second chromatographic column located between the second connection port and the detection unit; The third connection port is communicated with the second air intake pipe; the fourth connection port is communicated with the seventh connection port through a pipe provided with a quantitative pipe; the fifth connection port is communicated with the second exhaust pipe ; the sixth connection port is communicated with the third air intake pipe; the ninth connection port is communicated with the first exhaust pipe; the tenth connection port is communicated with the first air intake pipe; The first chromatographic column is a 125-1334 DB-624 chromatographic column from Agilent, USA; the second chromatographic column is a 19095N-126I HP-INNOWAX chromatographic column from Agilent, USA.

Preferably, the data acquisition and processing unit is connected to the detection unit through a circuit, and the data acquisition and processing unit has a display screen for displaying detection results and at least one data output interface.

Preferably, the carrier gas unit includes a carrier gas cylinder built in the box, and the carrier gas cylinder provides a first path of carrier gas and a second path of carrier gas through the first air inlet pipe and the second air inlet pipe, respectively. carrier gas.

Preferably, the ten-way valve has a first state, in which the first connection port communicates with the tenth connection port, and the second connection port communicates with the third connection port The fourth connection port communicates with the fifth connection port, the sixth connection port communicates with the seventh connection port, and the eighth connection port communicates with the ninth connection port.

Preferably, the ten-way valve has a second state, in which the first connection port communicates with the second connection port, and the third connection port communicates with the fourth connection port The fifth connection port is in communication with the sixth connection port, the seventh connection port is in communication with the eighth connection port, and the ninth connection port is in communication with the tenth connection port.

The present invention also provides an operation method of the above-mentioned gas detection device for benzene series, the method comprising the following steps:

The ten-way valve is adjusted to a first state by the control unit. In the first state, the first connection port communicates with the tenth connection port, and the second connection port communicates with the first connection port. Three connecting ports communicate with each other, the fourth connecting port communicates with the fifth connecting port, the sixth connecting port communicates with the seventh connecting port, and the eighth connecting port communicates with the ninth connecting port;

Start the sampling pump, collect the sample gas through the gas sampling unit, make the sample gas continuously pass into the third air inlet pipe, then enter the sixth connection port and enter the quantitative pipe from the seventh connection port, The gas flowing out from the quantitative pipe enters the fourth connection port and the fifth connection port and is evacuated through the second exhaust pipe;

At the same time, through the control unit, the first channel of carrier gas provided by the carrier gas unit is continuously passed into the tenth connection port and the first connection port through the first air inlet pipe, and then flows through the first chromatograph a column, the gas flowing out from the first chromatographic column enters the eighth connection port and the ninth connection port and is evacuated through the first exhaust pipe;

At the same time, through the control unit, the second path carrier gas provided by the carrier gas unit passes through the second intake pipe into the third connection port and the second connection port, and then passes through the third exhaust pipe After flowing through the second chromatographic column, the gas flowing out from the second chromatographic column enters the detection unit and is evacuated.

Preferably, the operating method further comprises the steps of:

The ten-way valve is adjusted from a first state to a second state by the control unit, and in the second state, the first connection port communicates with the second connection port, and the third connection port It communicates with the fourth connection port, the fifth connection port communicates with the sixth connection port, the seventh connection port communicates with the eighth connection port, and the ninth connection port communicates with the tenth connection port. connection port is connected;

At this time, through the sampling pump and the gas sampling unit, the collected sample gas is continuously passed into the third air inlet pipe, then enters the sixth connection port and the fifth connection port, and flows from the second exhaust pipe empty;

At the same time, through the control unit, the first carrier gas provided by the carrier gas unit is continuously passed into the tenth connection port and the ninth connection port through the first air inlet pipe, and then passes through the first exhaust gas. tube emptying;

At the same time, through the control unit, the second path carrier gas provided by the carrier gas unit passes through the second air inlet pipe into the third connection port and the fourth connection port, and then blows back into the quantitative pipe to The sample gas stored in the first state is pushed out of the quantitative tube, and then the sample gas flows into the seventh connection port and the eighth connection port, and is backflushed into the first chromatographic column. Under the action of the column, different gas components are decomposed and discharged at different speeds, and the decomposed gas to be tested is passed into the first connection port and the second connection port, and then flows to the second chromatograph through the third exhaust pipe. The column is separated by the second chromatographic column and then enters the detection unit for detection.

Preferably, the operating method further comprises the steps:

After the first chromatographic column desorbs and separates the sample gas for a predetermined time, the ten-way valve is adjusted from the second state to the first state by the control unit;

Through the sampling pump and the gas sampling unit, the collected sample gas is continuously passed into the third air inlet pipe, and then enters the sixth connection port and enters the quantitative pipe from the seventh connection port, The gas flowing out of the quantitative pipe enters the fourth connection port and the fifth connection port and is evacuated through the second exhaust pipe; in this way, all the gas in the second state is exhausted to be used in all The sample gas for the next analysis is stored in the quantitative tube;

At the same time, through the control unit, the first path of carrier gas provided by the carrier gas unit is continuously passed into the tenth connection port and the first connection port through the first air inlet pipe, and then blows back into the first connection port. A chromatographic column, all the original gas in the first chromatographic column is pushed out in reverse, and after entering the eighth connection port and the ninth connection port, it is evacuated through the first exhaust pipe;

At the same time, through the control unit, the second path carrier gas provided by the carrier gas unit is continuously passed into the third connection port and the second connection port through the second intake pipe, and then flows into the third exhaust gas The remaining gas to be tested in the third exhaust pipe continues to be pushed to the second chromatographic column, and then the components in the gas to be tested continue to be analyzed and discharged at different speeds through the second chromatographic column, and then discharged from the second chromatographic column. The gas flowing out of the second chromatographic column enters the detection unit for detection and then is evacuated; in this way, a cycle of gas analysis is completed in the first state; the analysis result obtained by the detection unit is further transmitted to the Data acquisition and processing unit.

The gas detection device for benzene series of the present invention provides an integral structure with all built-in and integrated in the box body, and each structure is stably connected in the box body as a whole, the structure is compact, easy to carry and transport, and is suitable for various outdoor environments. Emergency gas analysis and detection. And the gas separation unit with independent structure can easily form a highly integrated and easily interchangeable gas analyzer, which reduces the number of connecting pipes and the number of control valves, thereby effectively reducing system errors and improving system reliability and detection accuracy. In addition, the gas separation unit of the present invention intercepts and backflushes the post-resolved impurity peak gas through the first chromatographic column, which is beneficial to the improvement of the detection accuracy of the gas to be detected, and then the second chromatographic column is used to widen the peak spacing of each component, which improves the The detection degree of different components, especially trace components, improves the detection accuracy.

In addition, the specific combination of chromatographic columns used in the gas detection device of the present invention, in conjunction with the ten-way valve with a special structure and connection relationship of the present invention, is especially suitable for the detection of benzene series compounds in the atmosphere, which can be used without stopping the machine. Continuous testing and cleaning enables repeated testing in a relatively short period of time, avoiding systematic errors caused by external state changes, and making testing results more reliable and accurate.

Description of drawings

The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention. in,

1 shows a schematic structural diagram of a gas detection device for benzene series according to a specific embodiment of the present invention;

FIG. 2 shows a schematic diagram of the connection structure of a gas detection device for benzene series according to another specific embodiment of the present invention;

Fig. 3 shows the first state schematic diagram of the gas separation unit of the gas detection device for benzene series according to another specific embodiment of the present invention;

Fig. 4 shows the second state schematic diagram of the gas separation unit shown in Fig. 3;

FIG. 5 shows an exemplary detection result diagram of the gas detection device of the present invention;

Figures 6a-6e show the standard curves of different benzene series, respectively.

Detailed ways

In order to have a clearer understanding of the technical features, objects and effects of the present invention, the specific embodiments of the present invention will now be described with reference to the accompanying drawings. Wherein, the same parts use the same reference numerals.

As mentioned in the background section, due to the complex structure of existing gas analysis devices, such as gas chromatographs, etc., there are many connecting pipes, power supply and control cables, etc., the stability of the existing gas analysis devices is very poor, and the Easy to carry. Therefore, the present invention provides a gas detection device for benzene series, by simplifying the structure, integrating the necessary structures as much as possible, and reducing the number of connecting pipes and the number of control valves by reducing the number of parts of the separation system as much as possible , so that the system error can be effectively reduced, the detection accuracy of the gas analyzer can be improved while the reliability is improved, and a more practical gas detection device for benzene series can be obtained.

Specifically, referring to FIG. 1 , which shows a schematic structural diagram of a gas detection device for benzene series compounds according to a specific embodiment of the present invention, the figure shows that the gas detection device for benzene series compounds of the present invention includes: Box 100, box 100 is provided with gas sampling unit 11, and inside box 100 is provided with gas separation unit 12, detection unit 13, data acquisition and processing unit 14, control unit 15, carrier gas unit 16 and calibration unit 17 In addition, according to the needs of the pressure of the sampling gas source, the gas detection device for benzene series of the present invention can also have a built-in sampling pump 18 controlled by the control unit 15 in the box body 100 . The outer side of the box body 100 can also be provided with a terminal for an external power cord, or the terminal of the external power supply can be replaced with a USB power supply connector (not shown in the figure) that is convenient to connect to the vehicle power supply, which is also an alternative and feasible. Program. Of course, in a particularly compact and portable structure, a built-in battery in the box body 100 can also be used for emergency detection.

In addition, in the specific structure of the present invention, as shown in FIG. 2, it shows a schematic diagram of the connection structure of a gas detection device for benzene series according to another specific embodiment of the present invention, referring to FIGS. 1-2, The box body 100 is also provided with various structures such as cables connecting the data acquisition and processing unit 14 and the control unit 15, solenoid valves, etc., and correspondingly connected with the gas sampling unit 11, the gas separation unit 12, the detection unit 13, and the carrier gas. The structure of the unit 16 and the gas pipeline of the calibration unit 17, etc.

金属毛细柱和CP-Sil 43 CB类型的气相分离柱的组合形式；或者针对卤代化合物的分离检测，可以采用诸如

金属毛细柱和AE.OV-1301类型的气相分离柱的组合形式。当然，根据被检出目标物种种类及数量的不同，可以通过更换不同组别的色谱柱的方式来实现同样原理的气体成份的分离检测。其中

系列的金属毛细柱、CP-Sil 43 CB、AE.OV-1301为市售常用类型的气相分离柱的型号，其气体分析性能均可通过各种产品手册查询获得。另外分离箱120中还可以进一步设置恒温控制机构，避免室温波动干扰分析结果。In addition, the gas detection device for benzene series of the present invention also has a built-in gas separation unit 12 with an independent structure, which is arranged in an independent separation box 120, and the separation box 120 is provided with three connected to the inside thereof. Intake pipes 121, 122, 123 and three exhaust pipes 124, 125, 126. That is, the gas separation unit 12 disposed in the box 100 is designed as an independent structure, and there are only six pipes connecting the inside and outside of the separation box 120, namely three intake pipes 121, 122, 123 and three exhaust pipes. Pipes 124, 125, 126, and the interior of the separation box 120 is integrated with a gas-phase separation column suitable for a specific type of gas separation, for example, for the separation and detection of aromatic hydrocarbon compounds, such as

A combination of metal capillary column and CP-Sil 43 CB type gas phase separation column; or for the separation and detection of halogenated compounds, such as

Combination of metal capillary column and AE.OV-1301 type gas phase separation column. Of course, according to the type and quantity of the detected target species, the separation and detection of gas components with the same principle can be achieved by replacing different groups of chromatographic columns. in

The series of metal capillary columns, CP-Sil 43 CB, and AE.OV-1301 are the commonly used types of gas phase separation columns in the market, and their gas analysis performance can be obtained from various product manuals. In addition, a constant temperature control mechanism may be further set in the separation box 120 to prevent fluctuations in room temperature from interfering with the analysis results.

The gas separation unit 12 with an independent structure can form a highly integrated and easily interchangeable gas analyzer, that is, for different types of gas separation detection, gas separation boxes 120 of various specifications can be prefabricated. When the gas is analyzed, a corresponding type of gas separation box 120 can be installed in the box body 100, and only the six pipes of the gas separation box 120 need to be connected with the internal pipeline of the box body 100 to form a corresponding type. gas analyzer. In fact, in the specific embodiment shown in FIG. 2 , there are actually two exhaust pipes 124 and 126 of the six pipes of the gas separation box 120 that are directly discharged from the outside of the box 100 , that is, these two exhaust pipes 124 and 126 The pipes 124 and 126 are integrated on the gas separation box 120, and can be installed into the box body 100 without any joints. Therefore, only four pipe joints are required to replace a gas separation box 120.

Correspondingly, at an appropriate position of the box body 100 , an air inlet pipe of the gas sampling unit 11 and a passage for exhausting the three exhaust pipes 124 , 125 and 126 may be provided. In addition, according to the specific conditions of the sampled gas, in order to facilitate gas analysis, a filter joint 111 for preliminary dehumidification and dust removal can be set on the air inlet pipe of the gas sampling unit 11; The filter joint 111 directly filters the gas by the dust removal structure built in the gas sampling unit 11 .

That is, as can be seen from Figures 1-2, the gas detection device for benzene series of the present invention can provide an integral structure that is all built-in and integrated in the box, and each structure is stably connected in the box as a whole, and the structure is compact, It is easy to carry and transport, and is suitable for emergency gas analysis and detection in various field environments. And the gas separation unit with independent structure can easily form a highly integrated and easily interchangeable gas analyzer, which reduces the number of connecting pipes and the number of control valves, thereby effectively reducing system errors and improving system reliability and detection accuracy.

Further, the data acquisition and processing unit 14 shown in FIGS. 1-2 is connected to the detection unit 13 through a circuit, and the data acquisition and processing unit 14 has a display screen 141 for displaying detection results and at least one data output interface 142 . FIG. 1 specifically shows three data output interfaces 142 in the form of USB, and one of the data output interfaces 142 can also be set in the form of a card reader suitable for installing a memory card. The display screen 141 may be a liquid crystal display screen embedded in one side of the box body 100, or may be just a video output interface, which may be connected to an external display by means of a video cable. Alternatively, in another specific embodiment, the display screen 141 and the data output interface 142 can also be combined into a unified independent interface, such as a USB Type-C interface, according to the development of technology, through which an external interface can be connected of laptops for receiving inspection data and/or video signals, with better scalability.

In addition, as shown in FIG. 2 , the aforementioned three inlet pipes 121 , 122 and 123 are respectively the first inlet pipe 121 and the second inlet pipe 122 communicating with the carrier gas unit 16 , and the gas sampling unit 11 and the calibration unit 17 , respectively. the third intake pipe 123.

In addition, the aforementioned three exhaust pipes 124 , 125 and 126 are respectively the first exhaust pipe 124 and the second exhaust pipe 125 for venting, and the third exhaust pipe 126 which communicates with the detection unit 13 .

Further, the carrier gas unit 16 may include a carrier gas cylinder 161 built in the box body 100 , and the carrier gas cylinder 161 provides the first path of carrier gas and the second path of carrier gas through the first inlet pipe 121 and the second inlet pipe 122 respectively. gas. That is, the built-in carrier gas cylinder 161 in this embodiment can reduce the trouble of connecting the gas cylinder on site, reduce the system error, and avoid the redundant calibration process after temporary connection, which is especially suitable for emergency situations such as toxic gas leakage. Gas analysis detection. In addition, two paths of carrier gas are provided by a single carrier gas cylinder 161, which avoids systematic errors such as the flow rate and composition of different gas sources, and improves the detection accuracy. Of course, considering the portability problem, the built-in carrier gas cylinder 161 has a limited amount of carrier gas, and an interface connected in parallel with the carrier gas cylinder 161 can also be provided on the box 100 for connecting other high-pressure carrier gases during long-term on-site testing. gas cylinder. Since the flow rate and type of the carrier gas have a great influence on the results, the replacement of the external carrier gas source requires re-calibration. The calibration process will be further described below.

Further, the calibration unit 17 includes a calibration cylinder 171 and a dynamic calibrator 172 built in the box 100 , and the third intake pipe 123 communicates with the calibration cylinder 171 and the dynamic calibrator 172 through a three-way valve. Likewise, in this embodiment, the built-in calibration steel cylinder 171 can reduce the trouble of connecting the gas cylinder on site and reduce the system error. Using the calibration cylinder 171, rapid calibration can be performed, that is, by collecting the standard mixed gas of known concentration in the calibration cylinder 171 into the quantitative tube 203, and performing a normal separation and detection procedure, the peaks of each component are obtained, and the peak height, Quantitative data such as peak area are compared with the standard curve in the laboratory to determine whether the system state meets the formal measurement.

Additionally, the dynamic calibrator 172 in the calibration unit 17 may perform a multi-point dynamic calibration process. That is, the dynamic calibrator 172 is a multi-point calibration instrument. The dynamic calibrator 172 is used to prepare mixed gases of different known concentrations, and after the analysis results are obtained, the corresponding different gas concentrations and quantitative values (peak heights or peak areas) are plotted. A number of points will be obtained from which a standard curve can be drawn. Generally, when taking out the field for testing, the dynamic calibrator 172 does not need to be connected to the box body, and the calibration cylinder 171 can be kept connected continuously, that is, it is built into the box body. If the detection time is too long, a high-pressure gas cylinder with large capacity standard gas can also be connected. The calibration cylinder 171 can only have a fixed concentration, that is, it can only correspond to a point on the standard curve obtained by the dynamic calibrator 172. According to the deviation between this point and the curve, the working state of the instrument can be known, so it is called rapid calibration or also It can be called fast verification. This quick calibration system can be performed at the beginning or near the end of the field test, or the control system 15 can periodically execute the quick calibration 1-2 times a day through program settings.

In a specific embodiment, a sampling pump 18 may be provided in the second exhaust pipe 125 to provide a certain flow pressure, which facilitates gas sampling under normal pressure, and improves the efficiency and controllability of sampling and analysis. In the present embodiment, the sampling pump 18 is arranged at the end of the gas path. The sampling pump 18 itself may cause problems such as gas path connection and material adsorption. Compared with the sampling pump 18 installed at the front end of the gas path, its influence on the detection accuracy Therefore, in this embodiment, the sampling pump 18 is preferably placed at the rear, that is, the sampling pump 18 is arranged in the second exhaust pipe 125, which can reduce the interference caused by the sampling pump 18 itself, and is conducive to improving the detection accuracy.

The specific structure of the separation unit of the gas detection device for benzene series compounds of the present invention will be further described below with reference to FIGS. 3-4 , wherein FIG. A schematic diagram of the first state of the gas separation unit of the gas detection device; FIG. 4 shows a schematic diagram of the second state of the gas separation unit shown in FIG. 3 .

It is shown in the figure that the separation unit of the gas detection device for benzene series of the present invention includes a ten-way valve 20 disposed inside the separation box 120, the ten-way valve 20 having the first to the first numbered in the order of adjoining positions. Ten connection ports. Since there are too many connection ports of the ten-way valve 20 shown in the figure, it will be very confusing to label the specific reference numerals one by one in the figure. For a clearer understanding, in FIG. 3 and FIG. The numbers are numbered sequentially according to the adjacent positions. Each Arabic numeral corresponds to the connection port of the Chinese serial number with the same value. For example, the connection port corresponding to the Arabic numeral 1 indicates the first connection port in the subsequent description, and the connection port corresponding to the Arabic numeral 2 , in the subsequent description, it represents the second connection port, and so on.

The figure shows that the first connection port and the eighth connection port of the ten-way valve 20 of the separation unit 12 of the gas detection device for benzene series of the present invention are communicated through the pipeline provided with the first chromatographic column 201; the second The connection port is communicated with the third exhaust pipe 126, and the third exhaust pipe 126 is provided with a second chromatographic column 202 located between the second connection port and the detection unit 13; the third connection port is communicated with the second intake pipe 122; The fourth connection port is communicated with the seventh connection port through the pipeline provided with the quantitative pipe 203; the fifth connection port is communicated with the second exhaust pipe 125; the sixth connection port is communicated with the third air intake pipe 123; the ninth connection port is communicated with the first The exhaust pipe 124 is in communication; the tenth connection port is in communication with the first intake pipe 121 .

The operation method of the gas detection device for benzene series of the present invention will be described in detail below with reference to the accompanying drawings 1-4. By operating the process of gas analysis, the function and function of the connection structure of the separation unit 12 of the present invention can be more clearly understood .

As shown in Figures 1-4, the operation method of the gas detection device for benzene series of the present invention includes the following steps:

Referring first to FIG. 1 and FIG. 3 , the ten-way valve 20 is adjusted to the first state by the control unit 15 , that is, the ten-way valve 20 has a first state. In the first state, the first connection port is connected to the tenth state. The second connecting port communicates with the third connecting port, the fourth connecting port communicates with the fifth connecting port, the sixth connecting port communicates with the seventh connecting port, and the eighth connecting port communicates with the ninth connecting port.

Then, start the sampling pump 18, collect the sample gas through the gas sampling unit 11, make the sample gas continuously pass into the third air inlet pipe 123, then enter the sixth connection port and enter the quantitative pipe 203 from the seventh connection port, from the quantitative pipe 203 The outflowing gas enters the fourth connection port and the fifth connection port and is evacuated through the second exhaust pipe 125 . Through the continuous flow of the sample gas, a required predetermined amount of the sample gas is stored in the quantitative tube 203 to facilitate the next analysis and detection.

At the same time, through the control unit 15, the first channel of carrier gas provided by the carrier gas unit 16 is continuously passed into the tenth connection port and the first connection port through the first air inlet pipe 121, and then flows through the first chromatographic column 201, from the first chromatographic column 201. The gas flowing out of the column 201 enters the eighth connection port and the ninth connection port, and is then evacuated through the first exhaust pipe 124 .

At the same time, through the control unit 15 , the second path carrier gas provided by the carrier gas unit 16 passes through the second inlet pipe 122 into the third connection port and the second connection port, and flows through the second chromatographic column 202 through the third exhaust pipe 126 . , and then the gas flowing out from the second chromatographic column 202 enters the detection unit 13 and then is evacuated.

By using the first channel of carrier gas to sequentially clean the first chromatographic column 201 and the corresponding connection ports and pipelines, and to use the second channel of carrier gas to sequentially clean the second chromatographic column 202 and the detection unit 13 and then venting, the same gas can be used. The source realizes the cleaning of the system, the gas source is stable, and the efficiency is higher, which is conducive to the subsequent acquisition of more accurate detection results. After the cleaning is stable, the system reaches a preset state that can be analyzed and detected in the next step.

Afterwards, when the system reaches a predetermined stable state, the ten-way valve 20 can be adjusted from the first state shown in FIG. 3 to the second state shown in FIG. 4 through the control unit 15, that is, the ten-way valve 20 has a In the second state, in the second state shown in FIG. 4 , the first connection port is communicated with the second connection port, the third connection port is communicated with the fourth connection port, the fifth connection port is communicated with the sixth connection port, and the seventh connection port is communicated with The port communicates with the eighth connection port, and the ninth connection port communicates with the tenth connection port.

At this time, through the sampling pump 18 and the gas sampling unit 11 , the collected sample gas is continuously passed into the third inlet pipe 123 , then enters the sixth connection port and the fifth connection port, and is evacuated from the second exhaust pipe 125 . This process is used to maintain the flow of the sample gas in the pipeline, so that the next cycle of sampling will not be interrupted, so as to ensure the continuity of continuous online analysis, avoid data jumps that affect the detection accuracy, and ensure continuous positive pressure gas. The flow can prevent the outside air from entering the gas path and cause pollution, and ensure that the gas path is stable and clean, thereby further ensuring the accuracy of the analysis results.

At the same time, through the control unit 15 , the first path of carrier gas provided by the carrier gas unit 16 is continuously passed into the tenth connection port and the ninth connection port through the first air inlet pipe 121 , and then is evacuated through the first exhaust pipe 124 . In this way, the lines are continuously purged with the carrier gas, avoiding contamination and preparing for the next gas analysis.

At the same time, through the control unit 15, the second path carrier gas provided by the carrier gas unit 16 is passed through the second air inlet pipe 122 to the third connection port and the fourth connection port, and then backflushed into the quantitative pipe 203 to store it in the first state. The sample gas is pushed out of the quantitative tube 203, and then the sample gas flows into the seventh connection port and the eighth connection port, and is also backflushed into the first chromatographic column 201. Under the action of the first chromatographic column 201, different gas components move at different speeds. For analysis and discharge, the first analyzed gas is passed into the first connection port and the second connection port, and then flows to the second chromatographic column 202 through the third exhaust pipe 126 , and then enters the detection unit 13 for detection after being separated by the second chromatographic column 202 .

The second state shown in FIG. 4 looks similar to the separation and detection by connecting the first chromatographic column 201 and the second chromatographic column 202 in series on the surface. Then, the operation steps of the present invention are not simple series separation, but require The first chromatographic column 201 switches to the first state immediately after a predetermined time period has elapsed for the analytical separation of the sample gas.

That is, according to the characteristics of the first chromatographic column 201 , the time required for all the pre-analyzed gas to enter the third exhaust pipe 126 through the first chromatographic column 201 can be calculated or obtained experimentally. In time, the control unit 15 automatically starts the state transition, ie the ten-way valve 20 is adjusted by the control unit 15 from the second state to the first state.

At this time, all the gas resolved first has entered the third exhaust pipe 126, and a part of the gas resolved first may have reached the second chromatographic column 202 or even the detection unit 13 (this can be connected to the second chromatographic column 13 through the second connection port The volume of the third exhaust pipe 126 between the chromatographic columns 202 is flexibly set and depends on the width range of the target species segment). After that, the control unit 15 immediately switches from the second state to the first state, and the gas resolved in the latter stage of the first chromatographic column 201 is suddenly cut off and will no longer enter the third exhaust pipe 126 . That is, in this step of the present invention, the gas components in the sample gas that are first resolved from the first chromatographic column 201 need to be used as the gas to be measured, and the gas components that are resolved later from the first chromatographic column 201 are Useless impurity gas to avoid impurity peaks generated after this part of the gas enters the detection unit 13 and reduce the curve accuracy of the gas to be measured.

After switching to the first state, as shown in FIG. 3 , through the sampling pump 18 and the gas sampling unit 11, the collected sample gas is continuously passed into the third air inlet pipe 123, and then enters the sixth connection port and from the seventh connection port. Enter the quantitative pipe 203, the gas flowing out from the quantitative pipe 203 enters the fourth connection port and the fifth connection port and is evacuated through the second exhaust pipe 125; Sample gas for the next analysis is stored in 203 .

At the same time, the first channel of carrier gas provided by the carrier gas unit 16 is continuously passed into the tenth connection port and the first connection port through the first air inlet pipe 121 through the control unit 15 , and then backflushed into the first chromatographic column 201 . At this time, the first chromatographic column 201 originally retains the latter-stage desorption gas that has not yet flowed out. This part of the gas as waste gas is trapped when switching from the second state to the first state due to the slow passing speed. At this time, through the backflushing effect of the first channel of carrier gas, the gas originally remaining in the first chromatographic column 201 can be easily pushed out of the first chromatographic column 201 by the first channel of carrier gas through backflushing. With the continuous entry of the first channel of carrier gas, all the original gas in the first chromatographic column 201 can be pushed out in reverse, and after entering the eighth connection port and the ninth connection port, it is evacuated through the first exhaust pipe 124 . That is, in this step, by switching to the first state, the exhaust gas in the first chromatographic column 201 can be reversely blown clean by the first carrier gas. The forward purging efficiency will be very low, but through the reverse purging, the first chromatographic column 201 and related pipeline interfaces can be cleaned faster, the cleaning efficiency is higher, the time required is shorter, and the effect of purging and cleaning It is also much better than the forward purging, and it also avoids the long-term analysis that is difficult to purge in the forward purging from entering the detection unit 13 for the next analysis, thereby reducing the interference of impurities and improving the analysis results. precision.

Further at the same time, the control unit 15 allows the second path carrier gas provided by the carrier gas unit 16 to continuously flow into the third connection port and the second connection port through the second intake pipe 121 , and then flows into the third exhaust pipe 126 . At this time, the third exhaust pipe 126 is just the remaining gas to be measured that was just intercepted and resolved in the previous stage. After switching to the first state, the second carrier gas flows directly into the third exhaust pipe 126 to remove the remaining gas to be measured. The gas to be measured is pushed to the second chromatographic column 202, and then the components in the gas to be measured continue to be analyzed and discharged at different speeds through the second chromatographic column 202, and then the gas flowing out from the second chromatographic column 202 enters the detection unit 13 for detection. In this way, a cycle of gas analysis is completed in the first state; the analysis result obtained by the detection unit 13 is further transmitted to the data acquisition and processing unit 14 through the circuit.

In this step, since the impurity gas with a long resolution time was previously intercepted by the first chromatographic column 201 and did not enter the third exhaust pipe 126, it is really necessary to push the second carrier gas to the second chromatographic column 202. The gas components to be detected are analyzed, and the second chromatographic column 202 analyzes and discharges the gases to be tested with different components at different speeds, opening up the interval between the peaks of the curves of different gas components, avoiding mutual interference between adjacent peaks, and improving the performance of different components. In particular, the detection degree of trace components improves the detection accuracy.

In the present invention, the sample gas does not directly pass through the first chromatographic column 201 and the second chromatographic column 202 for serial analysis and detection, but before the detection, the first chromatographic column 201 performs an interception operation, and the first chromatographic column 201 is used to detect the sample. A pre-separation of the gas is carried out, the gas to be analyzed is directed to the second chromatographic column, and the waste gas of the latter stage is trapped in the first chromatographic column 201 through state switching, and then the waste gas is blown out to prepare for the next detection. The control unit 15 can set an appropriate time to perform state transition according to the characteristics of the first chromatographic column 201 , so as to intercept the waste gas in the latter stage except the gas to be analyzed and detected, and only analyze the gas to be tested in the front stage.

Example 1

The following takes the detection of benzene series compounds in the atmosphere as an example to further illustrate the features and technical effects of the present invention.

Due to production and domestic pollution, benzene series compounds can be widely detected in human living and living environments. And the human blood, nerves, reproductive system has a strong harm. The concentration of benzene series compounds in the atmosphere is one of the contents of routine monitoring of the atmospheric environment, and strict indoor and outdoor air quality standards are stipulated. Benzenes in the general sense mainly include benzene, toluene, ethylbenzene, xylene, trimethylbenzene, styrene, phenol, aniline, chlorobenzene, nitrobenzene, etc. Among them, due to Benzene, Toluene, Ethylbenzene (Ethylbenzene) and Xylene (Xylene) are four representative substances, and some people also call benzene series BTEX for short. Benzenes have serious negative effects on regional, especially urban atmospheric environment. Because most benzene-based compounds (such as benzene, toluene, etc.) have strong volatility, they are easily volatilized into the gas at room temperature to form volatile organic compounds (VOCs), which will cause VOCs gas pollution. For example, BTEX, as an organic solvent often used in industry, is widely used in paint, degreasing, dry cleaning, printing, textile, synthetic rubber and other industries. During the production, storage, transportation and use of BTEX, air pollution will be caused due to volatilization. BTEX has high photochemical reactivity in the atmosphere, and has a considerable effect on the formation of photooxidants (such as ozone and peroxyacetyl nitrate) and secondary organic aerosols in the atmosphere.

Therefore, the detection of benzene-based compounds in the atmosphere is taken as an example for further explanation.

Experimental conditions:

The first chromatographic column 201 adopts the 125-1334 DB-624 chromatographic column of Agilent, USA; the second chromatographic column 202 adopts the 19095N-126I HP-INNOWAX chromatographic column of Agilent of the United States.

Among them, the relevant parameters of Agilent 125-1334 DB-624 are: length 30m, diameter 0.530mm, film thickness 3.00mm, temperature range -20℃-260℃. The relevant parameters of Agilent 19095N-126I HP-INNOWAX are: length 60m, diameter 0.530mm, film thickness 1.00mm, temperature range 40℃-240℃.

The carrier gas flow rate was 45ml/min, the oven temperature was 40°C, the sampling time was 300s, and the injection time was 3600s.

FIG. 5 shows an example detection result diagram of the gas detection device of the present invention. The figure shows the curve of the sample data obtained by the detection unit 13 and processed by the data acquisition and processing unit 14 with the change of the sample injection time. Variety.

Among them, the peak P1 in the graph shown in Fig. 5 is an impurity peak and should be excluded. The process of judging it as an impurity peak is as follows: when a standard gas of a certain concentration (such as 20ppb) is introduced into the test, six peaks appear in the spectrum, and one peak appears when a 0ppb standard gas is introduced, which indicates that this is at 0ppb. The peaks that appeared were not the peaks of the benzene series, but were miscellaneous peaks. In addition, when different concentrations of benzene series are introduced for calibration, such as 10ppb, 20ppb, and 30ppb, the peak areas and peak heights of other substances change according to the proportional relationship, while the area and peak height of the first peak P1 It does not change with the concentration, which further proves that this peak is not a benzene series substance peak, but a miscellaneous peak. There are still many methods for judging peak P1 as a miscellaneous peak, which can be easily judged by those skilled in the art according to common knowledge in the art, which is not the protection scope of the present invention, and is only briefly described here to facilitate understanding of the content of the present invention.

In addition, the peaks P2, P3, P4, P5, P6, etc. shown in Fig. 5, through the calibration of various single-component benzene series compounds, according to the principle of the same peak retention time under the same conditions, it is easy to judge The material peaks with the above numbers correspond to benzene, toluene, ethylbenzene, m-p-xylene and o-xylene respectively. In the specific embodiment shown in Figure 5, the retention time of benzene represented by peak P2 is 10.03 minutes, the retention time of toluene represented by peak P3 is 15.52 minutes, the retention time of ethylbenzene represented by peak P4 is 26.84 minutes, and the peak P5 represents The retention time of m-para-xylene was 28.47 minutes, and the retention time of ortho-xylene represented by peak P6 was 34.48 minutes.

Figures 6a-6e respectively show the standard curves of different benzene series (wherein, the injection concentration gradients are 5, 10, 15, 20, 25, 30, and 40ppb, respectively). Wherein, Figure 6a is a standard curve diagram of the peak area and peak height of benzene of different concentrations obtained by the gas detection device calibration of the present invention, and similar Figures 6b-6e show toluene, ethylbenzene, m-paraxylene and Standard plot of peak areas and heights for ortho-xylene. The results of the experiment according to the concentration gradient show that the variance of the standard curve of the peak area and peak height corresponding to each peak is >0.99, and the linear correlation is good.

It should be understood by those skilled in the art that, since the standard curves of Figures 6a-6e of the present invention show that the peak area and peak height are well correlated with the concentration of the substance, after obtaining the detection results similar to Figure 5, The corresponding concentration value of benzene series can be obtained by using the peak height of each substance peak in Fig. 5 corresponding to the peak height in the standard curve. Of course, the peak area obtained by integrating the peaks of each substance in FIG. 5 corresponds to the peak area in the standard curve, and the corresponding concentration value of the benzene series can also be obtained. It should be noted that the concentration value of the actually detected benzene series can be obtained by using the standard curve of peak height and peak area. It is closer to 1. Therefore, in the actual detection process of the present invention, the concentration value calculated by the standard curve of the peak area is used.

Further, due to the special structure of the gas detection device of the present invention, it can help the first chromatographic column 201 to remove interference, and at the same time, it can also stretch the retention time of each substance, and then use the second chromatographic column 202 to detect the benzene series. The retention time of each component is further extended, so it can obtain the peaks P2-P6 of the benzene series in the separated state shown in Figure 5, which not only has a good separation effect, but also has a larger spacing between the peaks, and the retention time The range stability is good, which can greatly improve the efficiency of calculating the peak area. For example, when integrating the area of an existing curve, the inflection point is usually determined point by point along the curve and then the curve is fitted for integration. It is easy to integrate some fluctuations that do not belong to the peak area into the peak area, which not only calculates the time long, and the addition of the wave area also reduces the detection accuracy. In the present invention, due to the special structure of the gas detection device of the present invention, it can obtain a stable retention time range of the substance peak, so when integrating the peak area, only the curve of a specific time range can be intercepted for integration, and the substance peak can be integrated. Regions outside the range are automatically excluded, greatly improving the integration efficiency of peak areas. At the same time, due to the existence of various substances in the atmosphere, the curve obtained by the detection cannot be only a standard curve style containing 6 substance peaks. In addition to the 5 substance peaks of benzene series, there may also be other substances that are not detected by the first chromatographic column. The fluctuation peaks of the interference substances removed by 201, these fluctuation peaks exist outside the retention time range of the standard 5 substance peaks, therefore, the special structure of the present invention can change the region beyond the retention range of the standard 5 substance peaks from Therefore, the interference area of the interfering substances in the peak area integration algorithm can be removed, and the accuracy of the gas detection device of the present invention in the detection of benzene series compounds can be greatly improved.

Further, in the following table 1, taking the concentration of 20ppb as an example, the repeatable experimental results obtained by the gas detection device of the present invention are specifically given

Table 1: Repeatability Test Results

Conclusion: Calculate the relative standard deviation of all the analysis results. It can be seen that the relative standard deviation of the retention time, peak area and peak height obtained by repeated tests are all low, indicating that the gas detection device and its operation method of the present invention have good repeatability.

Among them, the first group of data for each peak in Table 1 refers to the blind test data of 20ppb concentration prepared by five components. Under standard operating conditions, 6 peaks were detected, the first peak was eliminated, and the rest The integrated peak areas of the five peaks are shown in the first group of data in Table 1. Using the standard curve to convert the peak areas of the first set of data in the table into concentration values, the concentrations of P2 to P6 species were 20.9, 19.96, 19.87, 19.69, and 20.17ppb, respectively. The actual concentration of the blind sample used for the assessment is 20ppb, and the measured concentration is within the allowable range of error, which proves that the gas detection device and its operation method of the present invention are effective.

Further, according to the air pollutant detection standard, it is usually only required to detect the concentration of benzene and toluene in the atmosphere. Therefore, through the gas detection device of the present invention, it is only necessary to install the detection device of the present invention after the detection of benzene and toluene is completed. Switching from the second state to the first state, intercepting the flow of the gas to be tested, and blowing the remaining gas backward through the carrier gas, the required detection concentrations of benzene and toluene can be efficiently obtained, which can further improve the detection efficiency.

For example, in the graph of the detection results shown in Figure 5, the retention times for benzene and toluene end at about 16 minutes, while the retention time for ethylbenzene is after about 25 minutes, so it can be intercepted at about 20 minutes operation to switch from the second state to the first state. That is to say, the gas detection device of the present invention can carry out the interception and backflushing operation at any time as required without interrupting the operation through the special ten-way valve structure. Moreover, the carrier gas cleaning process of the system can be maintained in the interval of the interception operation, multiple sets of detection operations can be repeated in a relatively short period of time, and detection errors can be eliminated through the efficiently obtained multiple sets of detection results. In a word, because the gas detection device of the present invention adopts the design mode of interception and backflushing, the interception operation can be carried out as required, which is not only conducive to the efficient detection of the components to be detected, but also can be arbitrarily stopped according to the need. It will not cause any interference to the already detected results, which can greatly improve the detection efficiency. For example, if you want to detect the concentration of benzene, toluene, and ethylbenzene, you only need to switch the interception in about 30 minutes. The operation is simple and reliable, and a lot of purging operation time can be saved.

In addition, it should be noted that since different detection states have a great influence on the detection results, obtaining multiple sets of data efficiently in the shortest possible time can greatly improve the detection accuracy. The detection device simply connected in series in the prior art lacks the ten-way valve of the present invention that can efficiently intercept and convert, and its detection requires a lot of time to clean the carrier gas, which takes a long time, and the time interval for obtaining multiple sets of data is also very long. As a result, the equipment status of each test data is very different, the reliability of the test results is very poor, and it is difficult to obtain accurate test results. The non-stop operation detection and cleaning structure of the present invention can perform repeated detection in a relatively short period of time, which is also a particularly prominent advantage of the present invention over the prior art, and the obtained detection results are more reliable and more accurate. .

Those skilled in the art should understand that although the present invention is described in terms of multiple embodiments, not each embodiment only includes an independent technical solution. This description in the description is only for the sake of clarity, and those skilled in the art should understand the description as a whole, and regard the technical solutions involved in each embodiment as being able to be combined into different embodiments to understand the present invention scope of protection.

The above descriptions are only exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by any person skilled in the art without departing from the concept and principles of the present invention shall fall within the protection scope of the present invention.

Claims (6)

1. A gas detection device for benzene series substances comprises a box body (100), and is characterized in that the box body (100) is provided with a gas sampling unit (11), and a gas separation unit (12), a detection unit (13), a data acquisition and processing unit (14), a control unit (15) and a carrier gas unit (16) are arranged in the box body (100); wherein the gas separation unit (12) is arranged in an independent separation box (120), and the separation box (120) is provided with three air inlet pipes (121, 122, 123) and three air outlet pipes (124, 125, 126) communicated with the interior of the separation box; the three gas inlet pipes (121, 122, 123) are respectively a first gas inlet pipe (121) and a second gas inlet pipe (122) which are communicated with the carrier gas unit (16), and a third gas inlet pipe (123) which is communicated with the gas sampling unit (11); the three exhaust pipes (124, 125, 126) are respectively a first exhaust pipe (124) and a second exhaust pipe (125) for emptying, and a third exhaust pipe (126) communicated with the detection unit (13), and a sampling pump (18) is arranged in the second exhaust pipe (125);

the gas separation unit (12) includes a ten-way valve (20) disposed inside the separation tank (120), the ten-way valve (20) having first to tenth connection ports numbered in order of adjoining positions; the first connecting port is communicated with the eighth connecting port through a pipeline provided with a first chromatographic column (201); the second connecting port is communicated with the third exhaust pipe (126), and the third exhaust pipe (126) is provided with a second chromatographic column (202) positioned between the second connecting port and the detection unit (13); the third connecting port is communicated with the second air inlet pipe (122); the fourth connecting port is communicated with the seventh connecting port through a pipeline provided with a quantitative pipe (203); the fifth connecting port is communicated with the second exhaust pipe (125); the sixth connecting port is communicated with the third air inlet pipe (123); the ninth connection port is communicated with the first exhaust pipe (124); the tenth connecting port is communicated with the first air inlet pipe (121);

the first chromatographic column (201) adopts a chromatographic column with the model number of 125-1334DB-624 of Agilent company in America; the second chromatographic column (202) adopts a model 19095N-126I HP-INNOWAX chromatographic column of Agilent company;

the carrier gas unit (16) comprises a carrier gas steel cylinder (161) which is arranged in the box body (100), and the carrier gas steel cylinder (161) provides a first path of carrier gas and a second path of carrier gas through the first gas inlet pipe (121) and the second gas inlet pipe (122) respectively.

2. The gas detection apparatus according to claim 1, wherein the ten-way valve (20) has a first state in which the first connection port communicates with the tenth connection port, the second connection port communicates with the third connection port, the fourth connection port communicates with the fifth connection port, the sixth connection port communicates with the seventh connection port, and the eighth connection port communicates with the ninth connection port.

3. The gas detection apparatus according to claim 1, wherein the ten-way valve (20) has a second state in which the first connection port communicates with the second connection port, the third connection port communicates with the fourth connection port, the fifth connection port communicates with the sixth connection port, the seventh connection port communicates with the eighth connection port, and the ninth connection port communicates with the tenth connection port.

4. A method of operating the benzene-based gas sensor apparatus according to claim 1, comprising the steps of:

adjusting the ten-way valve (20) to a first state by the control unit (15), in which the first connection port communicates with the tenth connection port, the second connection port communicates with the third connection port, the fourth connection port communicates with the fifth connection port, the sixth connection port communicates with the seventh connection port, and the eighth connection port communicates with the ninth connection port;

the sampling pump (18) is started, sample gas is collected through the gas sampling unit (11), the sample gas is continuously introduced into the third gas inlet pipe (123), then enters the sixth connecting port and enters the quantitative pipe (203) from the seventh connecting port, and gas flowing out of the quantitative pipe (203) enters the fourth connecting port and the fifth connecting port and then is exhausted through the second gas exhaust pipe (125);

meanwhile, the control unit (15) enables the first path of carrier gas provided by the carrier gas unit (16) to continuously enter the tenth connecting port and the first connecting port through the first gas inlet pipe (121), then the first path of carrier gas flows through the first chromatographic column (201), and the gas flowing out of the first chromatographic column (201) enters the eighth connecting port and the ninth connecting port and then is exhausted through the first exhaust pipe (124);

meanwhile, a second path of carrier gas provided by the carrier gas unit (16) is led into the third connecting port and the second connecting port through the second gas inlet pipe (122) by the control unit (15), then flows through the second chromatographic column (202) through the third gas outlet pipe (126), and then flows out of the second chromatographic column (202) to enter the detection unit (13) and is exhausted.

5. The method of operation of claim 4, further comprising the steps of:

adjusting the ten-way valve (20) from a first state to a second state by the control unit (15), in the second state, the first connection port communicates with the second connection port, the third connection port communicates with the fourth connection port, the fifth connection port communicates with the sixth connection port, the seventh connection port communicates with the eighth connection port, and the ninth connection port communicates with the tenth connection port;

at the moment, the collected sample gas is continuously introduced into the third gas inlet pipe (123) through the sampling pump (18) and the gas sampling unit (11), then enters the sixth connecting port and the fifth connecting port and is exhausted from the second exhaust pipe (125);

meanwhile, the control unit (15) enables the first path of carrier gas provided by the carrier gas unit (16) to continuously enter the tenth connecting port and the ninth connecting port through the first gas inlet pipe (121), and then the first path of carrier gas is exhausted through the first exhaust pipe (124);

meanwhile, a second path of carrier gas provided by the carrier gas unit (16) is introduced into the third connector and the fourth connector through the second gas inlet pipe (122) through the control unit (15), then enters the quantitative tube (203) in a back flushing manner to push the sample gas stored in the quantitative tube (203) in the first state out of the quantitative tube (203), then the sample gas flows into the seventh connector and the eighth connector, enters the first chromatographic column (201) in a back flushing manner, different gas components are analyzed and discharged at different speeds under the action of the first chromatographic column (201), the gas to be detected analyzed is introduced into the first connector and the second connector, then flows to the second chromatographic column (202) through the third gas outlet pipe (126), and enters the detection unit (13) for detection after being separated by the second chromatographic column (202).

6. The method of operation of claim 5, further comprising the steps of:

after the first chromatographic column (201) performs analytical separation on the sample gas for a preset time, the ten-way valve (20) is adjusted from the second state to the first state through the control unit (15);

continuously introducing the collected sample gas into the third gas inlet pipe (123) through the sampling pump (18) and the gas sampling unit (11), then entering the sixth connecting port and entering the quantitative pipe (203) from the seventh connecting port, and exhausting the gas flowing out of the quantitative pipe (203) after entering the fourth connecting port and the fifth connecting port through the second gas exhaust pipe (125); thereby discharging the gas in the second state entirely for storing the sample gas for the next analysis in the quantitative tube (203);

meanwhile, the control unit (15) enables the first path of carrier gas provided by the carrier gas unit (16) to continuously enter the tenth connecting port and the first connecting port through the first gas inlet pipe (121), then the first path of carrier gas enters the first chromatographic column (201) in a back blowing mode, all original gas in the first chromatographic column (201) is reversely pushed out, and then the first path of carrier gas enters the eighth connecting port and the ninth connecting port and is exhausted through the first exhaust pipe (124);

meanwhile, a second path of carrier gas provided by the carrier gas unit (16) is continuously introduced into the third connecting port and the second connecting port through the second gas inlet pipe (121) by the control unit (15), then flows into the third exhaust pipe (126), the residual gas to be detected in the third exhaust pipe (126) is continuously pushed to the second chromatographic column (202), then the components in the gas to be detected are continuously analyzed and discharged at different speeds through the second chromatographic column (202), and then the gas flowing out of the second chromatographic column (202) enters the detection unit (13) for detection and then is exhausted; thereby completing a cycle of gas analysis in said first state; the analysis result obtained by the detection unit (13) is further transmitted to the data acquisition and processing unit (14) through a circuit.

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