CN108037217A - A kind of Portable exhaust gas analyzer and its operating method - Google Patents

Abstract

The invention proposes a portable gas analyzer, which includes a box body, the box body is provided with a gas sampling unit, and the inside of the box body is provided with a gas separation unit, a detection unit, a data acquisition and processing unit, a control unit and a carrier gas Unit and calibration unit; wherein, the gas separation unit is set in an independent separation box, and the separation box is provided with three inlet pipes and three exhaust pipes communicating with its interior. In addition, the present invention also provides an operation method of the above-mentioned portable gas analyzer. The portable gas analyzer of the present invention provides a whole structure integrated in the box, which is easy to carry and transport, and is suitable for emergency gas analysis and detection in various field environments. The gas separation unit with an independent structure can easily form a highly integrated and interchangeable gas analyzer, which reduces the number of connecting pipes and control valves, effectively reduces system errors, and improves system reliability and detection accuracy.

Description

A portable gas analyzer and its operating method

technical field

The invention relates to gas detection and analysis technology in the field of environmental protection, in particular to an analyzer that can be used to analyze gas components, especially a portable gas analyzer and its operating method.

Background technique

In the field of environmental protection, it is often necessary to detect and analyze various gases, and gas chromatography is usually used. A gas chromatograph is a device for analyzing and testing mixed samples, usually including a gas circuit system, a sampling system, a separation system, a circuit control system, a detection system, a data acquisition and processing system, etc. However, the existing gas chromatographs are generally installed in the laboratory, and the overall volume is very large. Complex airflow pipes, various power supply and control cables, etc. need to be connected between each system, and the connection reliability of the entire device is very unstable. , if there is a slight change, the calibration needs to be rechecked, basically there is no possibility of easy portability.

CN 106841483 A discloses a chromatographic sampling separation device, which uses an eight-way valve and a ten-way valve in combination 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. As a result, 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. And more gas pipelines require a large number of connecting pipelines. The more pipelines, the greater the error caused by the gas pipeline volume, and the greater the influence of pipeline materials on the adsorption of gas components. In addition, the more pipes there are, the more prone to connection failures will occur at the joints, and the time for calibration and troubleshooting will be greatly increased, and the reliability of the system will thus deteriorate. However, the use of two sets of valves brings synchronization problems, 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 use for portable emergency sampling and analysis.

CN 104374860 A discloses a portable gas analyzer, which uses 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 of the prior art is very crude, only illustrating that it includes a box body, an automatic sampling mechanism, a sample gas separation mechanism and a chromatographic detection mechanism are arranged in the box body, and the automatic sampling mechanism includes ten channels. The valve, sampling ring, and mixed gas separation mechanism mainly include coarse separation column, subdivision chromatography column, auxiliary pipeline and insulation cotton, and the mixed gas detection mechanism mainly includes fuel cell and auxiliary pipeline. As for the delivery of the gas, the calibration of the equipment, the control of the equipment, 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, the existing technology uses two chromatographic columns to separate the gas, and removes the influence of impurities by connecting them in series. During use, the two chromatographic columns are kept in continuous series connection, one state sampling plus cleaning pipeline, one state Injection analysis. However, the dual chromatographic columns of this prior art are continuously used in series, and can only selectively highlight the species of the target section according to the two columns, thereby ignoring the remaining sections. The peak shapes of the different components of different components are widened, and the peak shapes of the species in the target section are not subdivided enough, so the accuracy of the analysis results needs to be improved.

Contents of the invention

The technical problem to be solved by the present invention is to provide a portable gas analyzer and its operating method, so as to reduce or avoid the aforementioned problems.

Specifically, the present invention provides a portable gas analyzer, 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 portable gas analyzer, which includes a box body, the box body is provided with a gas sampling unit, and the inside of the box body is provided with a gas separation unit, a detection unit, a data acquisition unit and a A processing unit, a control unit, a carrier gas unit, and a calibration unit; wherein, the gas separation unit is arranged in an independent separation box, and the separation box is provided with three inlet pipes and three exhaust pipes communicating with its interior.

Preferably, the three inlet pipes are respectively a first inlet pipe and a second inlet pipe connected to the carrier gas unit, and a third inlet pipe connected to the gas sampling unit and the calibration unit.

Preferably, the three exhaust pipes are respectively a first exhaust pipe and a second exhaust pipe for emptying, and a third exhaust pipe connected to the detection unit.

Preferably, the data collection and processing unit is connected to the detection unit through a circuit, and the data collection 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 the first path of carrier gas and the second path of gas through the first inlet pipe and the second inlet pipe respectively. carrier gas.

Preferably, the calibration unit includes a calibration cylinder and a dynamic calibrator built in the box, the third inlet pipe communicates with the calibration cylinder and the dynamic calibrator through a three-way valve, and the third A sampling pump is arranged in the intake pipe.

Preferably, the gas separation unit includes a ten-way valve arranged inside the separation box, and the ten-way valve has first to tenth connection ports numbered sequentially according to adjacent positions; wherein, the first connection port It communicates with the second exhaust pipe; the second connection port communicates with the ninth connection port through a pipeline provided with the first chromatographic column; the third connection port communicates with the third exhaust pipe, and the The third exhaust pipe is provided with a second chromatographic column located between the third connection port and the detection unit; the fourth connection port communicates with the second air intake pipe; the fifth connection port communicates with the The first exhaust pipe is in communication; the sixth connection port is in communication with the third intake pipe; the seventh connection port is in communication with the tenth connection port through a pipeline provided with a quantitative tube; the eighth connection port is in communication with the tenth connection port; The first air intake pipe communicates.

In addition, the present invention also provides a method for operating the above-mentioned portable gas analyzer, the method comprising the following steps:

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

Start the sampling pump, collect sample gas through the gas sampling unit, make the sample gas continuously flow into the third inlet pipe, then enter the sixth connection port and enter the quantitative tube from the seventh connection port, The gas flowing out from the metering tube enters the tenth connection port and the first connection port and then is emptied through the second exhaust pipe;

At the same time, through the control unit, the first carrier gas provided by the carrier gas unit is continuously passed into the eighth connection port and the ninth connection port through the first air intake pipe, and then flows through the first chromatographic Column, the gas flowing out from the first chromatographic column enters the second connecting port and the third connecting port and flows through the second chromatographic column through the third exhaust pipe, and then the gas flowing out from the second chromatographic column After the gas enters the detection unit, it is emptied;

At the same time, through the control unit, the second path of carrier gas provided by the carrier gas unit passes through the second inlet pipe into the fourth connection port and the fifth connection port, and then passes through the first exhaust pipe emptying.

Preferably, the operation method further comprises the steps of:

The ten-way valve is adjusted from the first state to the second state by the control unit, 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. The connection port is connected;

Through the sampling pump and the gas sampling unit, the collected sample gas is continuously passed into the third inlet pipe, then enters the sixth connection port and the fifth connection port and is emptied from the first exhaust pipe ;

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 eighth connection port and the seventh connection port through the first air inlet pipe, and then enters the quantitative tube to discharge the The sample gas stored therein in the first state is pushed out of the quantitative tube, and then the sample gas flows into the tenth connection port and the ninth connection port and enters the first chromatographic column, and the firstly resolved gas components in the sample gas are directly Evacuate, separate the latter stage of the gas and prepare it as the gas to be tested, the first desorbed gas flowing out of the first chromatographic column enters the second connection port and the first connection port and then passes through the second exhaust pipe and then empties ;

At the same time, through the control unit, the second carrier gas provided by the carrier gas unit passes through the second inlet pipe into the fourth connection port and the third connection port, and then passes through the third exhaust pipe The gas flows through the second chromatographic column, and then the gas flowing out from the second chromatographic column enters the detection unit and then is emptied.

Preferably, the operation method further comprises the steps of:

The control unit adjusts the ten-way valve from the second state to the third state, and the connection relationship of the ten-way valve in the third state is the same as that in the first state, wherein the first connection The 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, and the sixth connection port communicates with the first connection port. The seven connection ports are connected, and the eighth connection port is connected to the ninth connection port;

Through the sampling pump and the gas sampling unit, the collected sample gas is continuously passed into the third inlet pipe, then enters the sixth connection port and enters the quantitative tube from the seventh connection port, from the quantitative The gas flowing out of the pipe enters the tenth connection port and the first connection port and then is emptied through the second exhaust pipe; thus all the gas in the second state is discharged for storage in the quantitative tube Sample gas for the next analysis;

At the same time, through the control unit, the first carrier gas provided by the carrier gas unit is continuously passed into the eighth connection port and the ninth connection port through the first air intake pipe, and then flows through the first chromatographic column, the gas flowing out from the first chromatographic column pushes the gas to be tested separated in the second state into the second connection port and the third connection port, and then flows through the third exhaust pipe through the The second chromatographic column, through the second chromatographic column, the components in the gas to be tested are analyzed and discharged at different speeds, and then the gas flowing out from the second chromatographic column enters the detection unit and then is emptied; In the third state, a cycle of gas analysis is completed; the analysis result obtained by the detection unit is further transmitted to the data acquisition and processing unit through the circuit;

At the same time, through the control unit, the second path of carrier gas provided by the carrier gas unit passes through the second inlet pipe into the fourth connection port and the fifth connection port, and then passes through the first exhaust pipe Evacuation; in this way, all the gas in the second state is exhausted, and the pipeline is cleaned by the carrier gas to prepare for the next gas analysis.

The portable gas analyzer of the present invention provides an overall structure integrated in the box body, each structure is stably connected in the box body, compact in structure, easy to carry and transport, and suitable for emergency gas analysis and detection in various field environments. And the gas separation unit with an independent structure can easily form a highly integrated and interchangeable gas analyzer, reducing 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 uses the first chromatographic column to empty the miscellaneous peak gas analyzed earlier, which is beneficial to the improvement of the detection accuracy of the gas to be detected, and then uses the second chromatographic column to widen the peak distance of each component to improve the concentration of different components. Especially the detection degree of trace components improves the detection accuracy.

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,

What Fig. 1 shows is the structural representation of the portable gas analyzer according to a specific embodiment of the present invention;

What Fig. 2 shows is the connection structure schematic diagram of the portable gas analyzer according to another specific embodiment of the present invention;

Fig. 3 shows the first and third state schematic diagrams of the gas separation unit of the portable gas analyzer according to yet another specific embodiment of the present invention;

Fig. 4 is a schematic view showing the second state of the gas separation unit shown in Fig. 3 .

Detailed ways

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

As mentioned in the background technology 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., resulting in poor stability of the existing gas analysis devices. Easy to carry. Therefore, the present invention provides a portable gas analyzer. By simplifying the structure, the necessary structures are integrated as much as possible, and the number of connecting pipes and control valves is reduced by reducing the number of parts of the separation system as much as possible, thereby effectively reducing the The system error improves the detection accuracy of the gas analyzer while improving the reliability, so as to obtain a more practical portable gas analyzer.

Referring specifically to Fig. 1, what it shows is a schematic structural view of a portable gas analyzer according to a specific embodiment of the present invention. It is shown in the figure that the portable gas analyzer of the present invention includes a box body 100, and the box body 100 is provided with a gas The sampling unit 11, the inside of the box body 100 is provided with a gas separation unit 12, a detection unit 13, a data acquisition and processing unit 14, a control unit 15, a carrier gas unit 16 and a calibration unit 17; in addition, according to the pressure situation of the sampling gas source As required, the portable gas analyzer 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 box body 100 can also be provided with the terminal post that is used for external power supply line, perhaps replaces the terminal post of external power supply with the USB power supply joint (not shown) that is convenient to connect vehicle power supply, also is a kind of alternative 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 portable gas analyzer according to another specific embodiment of the present invention. Referring to FIGS. 1-2, there is also a It is equipped with various structures such as cables and solenoid valves connecting the data acquisition and processing unit 14 and the control unit 15, and correspondingly communicates with the gas sampling unit 11, the gas separation unit 12, the detection unit 13, the carrier gas unit 16 and the calibration unit 17 gas pipeline and other structures.

In addition, a gas separation unit 12 of independent structure is also built in the portable gas analyzer of the present invention, which is arranged in an independent separation box 120, and the separation box 120 is provided with three inlet pipes 121, 122 communicating with its interior. , 123 and three exhaust pipes 124,125,126. That is, the gas separation unit 12 arranged in the box body 100 is designed as an independent structure, and on the outside of the separation box 120, there are only six pipes communicating with the inside and outside, which are respectively three inlet pipes 121, 122, 123 and three exhaust pipes. Pipes 124, 125, 126, and the inside of the separation box 120 is integrated with a gas phase separation column suitable for specific types of gas separation, for example, for the separation and detection of aromatic hydrocarbon compounds, such as Combination of metal capillary column and BP-5 type gas phase separation column; or for the separation and detection of halogenated compounds, such as KB-VOC and Combination of gas phase separation columns of the metal capillary type. in The series of metal capillary columns, BP-5, and KB-VOC are commonly used types of gas phase separation columns on the market, and their gas analysis performance can be obtained through various product manuals. In addition, a constant temperature control mechanism may be further provided in the separation box 120 to prevent room temperature fluctuations from interfering with the analysis results.

The gas separation unit 12 with an independent structure can form a highly integrated and conveniently 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, the corresponding type of gas phase separation column 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 pipes of the box body 100 to form a corresponding type of gas phase separation column. gas analyzer. In fact, in the specific embodiment shown in FIG. 2, the six pipes of the gas separation box 120 actually have two exhaust pipes 124 and 126 that are used for exhausting, which are directly discharged from the outside of the box body 100, that is, these two The two pipelines 124 and 126 are integrated on the gas separation box 120. When the box body 100 is packed into the box body 100, no joints can be used at all. Therefore, only four pipeline joints are required to replace a gas separation box 120.

Correspondingly, at a suitable position of the box body 100 , an inlet pipe of the gas sampling unit 11 and a channel for exhausting the three exhaust pipes 124 , 125 , 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 provided on the inlet pipe of the gas sampling unit 11; of course, it can also be used in a dry and dust-free environment. The filter joint 111 directly filters the gas through the built-in dust removal structure of the gas sampling unit 11 .

That is, as can be seen from Figures 1-2, the portable gas analyzer of the present invention can provide an overall structure that is fully integrated in the box, and each structure is stably connected as a whole in the box, with a compact structure that is easy to carry and transport. It is suitable for emergency gas analysis and detection in various field environments. And the gas separation unit with an independent structure can easily form a highly integrated and interchangeable gas analyzer, reducing 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 collection and processing unit 14 shown in FIGS. 1-2 is connected to the detection unit 13 through a circuit, and the data collection 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 embedded in one side of the box body 100, or may be only a video output interface, which may be connected to an external display through a video cable. Or, in another specific embodiment, the display screen 141 and the data output interface 142 can also be combined into a unified independent interface according to the technical development, such as a USB Type-C interface, through which an external A laptop computer is used to receive 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 that communicate with the carrier gas unit 16, and communicate with the gas sampling unit 11 and the calibration unit 17. The third intake pipe 123.

In addition, the aforementioned three exhaust pipes 124 , 125 , 126 are respectively the first exhaust pipe 124 and the second exhaust pipe 125 for emptying, and the third exhaust pipe 126 connected to 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 carrier gas and the second carrier gas through the first inlet pipe 121 and the second inlet pipe 122 respectively. gas. That is to say, the present embodiment can reduce the trouble of connecting the gas cylinder on site through the built-in carrier gas cylinder 161, reduce the system error, and avoid the redundant calibration process after the temporary connection, and 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 flow rate and composition of different gas sources, and improves detection accuracy. Of course, considering the problem of portability, the built-in carrier gas cylinder 161 has a limited amount of gas, and an interface connected in parallel with the carrier gas cylinder 161 can also be provided on the box 100 for external connection of other high-pressure carrier gases during long-term on-site testing. cylinder. Since the flow rate and type of carrier gas have a great influence on the results, changing the external carrier gas source requires re-calibration. The calibration process will be further explained below.

Further, the calibration unit 17 includes a calibration cylinder 171 and a dynamic calibrator 172 built in the box 100 , and the third air inlet pipe 123 communicates with the calibration cylinder 171 and the dynamic calibrator 172 through a three-way valve. Similarly, in this embodiment, the built-in calibration cylinder 171 can reduce the trouble of connecting gas cylinders on site and reduce system errors. Utilize calibration steel cylinder 171, can carry out fast calibration, namely, by collecting the standard mixed gas of known concentration in the calibration cylinder 171 in the quantitative tube 203, carry out normal separation detection procedure, obtain each component sub-peak, through peak height, Quantitative data such as peak area are compared with the standard curve of the laboratory to determine whether the system status meets the formal measurement.

In addition, the dynamic calibrator 172 in the calibration unit 17 can perform a multi-point dynamic calibration process: that is, the dynamic calibrator 172 is a multi-point calibration instrument, and the mixed gas with different known concentrations is prepared through the dynamic calibrator 172, and the analysis results are obtained by detection Afterwards, multiple points will be obtained by plotting corresponding to different gas concentrations and quantitative values (peak height or peak area), and a standard curve can be obtained from these points. Generally, when it is taken out for on-site testing, the dynamic calibrator 172 may not be connected to the box, and the calibration cylinder 171 may be kept in a continuous connection state, that is, built in the box. If the detection time is too long, a high-pressure gas cylinder with a large capacity of standard gas can also be connected externally. The calibration cylinder 171 can only be of fixed concentration, that is, it can only go 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 status of the instrument can be known, so it is called quick calibration or also It can be called quick verification. This quick calibration system can be performed at the beginning or near the end of the on-site test, or it can be set by the program every day and the control system 15 can regularly perform quick calibration 1-2 times.

In a specific embodiment, a sampling pump 18 may be provided in the third air inlet pipe 123 to provide a certain flow pressure to facilitate gas sampling under normal pressure and improve the efficiency and controllability of sampling analysis. In this embodiment, the purpose of setting the sampling pump 18 is to realize the forced flow of the air flow. In the connection structure of the present invention, to realize the forced flow of the air flow, the sampling pump 18 can only be arranged in the third air intake pipe 123, and its position Can not be changed at will.

The specific structure of the separation unit of the portable gas analyzer of the present invention will be further described below with reference to FIGS. and a schematic diagram of the third state; FIG. 4 shows a schematic diagram of the second state of the gas separation unit shown in FIG. 3 .

As shown in the figure, the separation unit of the portable gas analyzer of the present invention includes a ten-way valve 20 disposed inside the separation box 120, and the ten-way valve 20 has the first to tenth connection ports numbered in sequence according to the adjacent positions. Because there are too many connection ports of the ten-way valve 20 in the figure, it will be very confusing to mark specific reference numerals one by one in the figure. In order to understand more clearly, in Fig. 3 and Fig. The numbers are numbered sequentially according to the adjacent positions, and each Arabic numeral corresponds to the connection port of the Chinese serial number of the same value, for example, the connection port corresponding to the Arabic number 1, which means the first connection port in the follow-up instructions, and the connection port corresponding to the Arabic number 2 , indicates the second connection port in subsequent descriptions, and so on.

Shown in the figure, the ten-way valve 20 of the separation unit 12 of the portable gas analyzer of the present invention, its first connecting port communicates with the second exhaust pipe 125; The pipeline of column 201 is communicated; The third connecting port is communicated with the 3rd exhaust pipe 126, and the 3rd exhaust pipe 126 is provided with the second chromatographic column 202 between the 3rd connecting port and detection unit 13; The 4th connecting port is connected with The second air intake pipe 122 communicates; the fifth connection port communicates with the first exhaust pipe 124; the sixth connection port communicates with the third air intake pipe 123; the seventh connection port communicates with the tenth connection port through a pipeline provided with a quantitative tube 203 ; The eighth connection port communicates with the first intake pipe 121 .

The operation method of the portable gas analyzer of the present invention will be described in detail below with reference to accompanying drawings 1-4. By operating the process of gas analysis, the functions and effects 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 operating method of the portable gas analyzer of the present invention comprises the following steps:

Referring first to 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, and in the first state, 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.

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

At the same time, the first path of carrier gas provided by the carrier gas unit 16 is continuously introduced into the eighth connection port and the ninth connection port through the first air inlet pipe 121 through the control unit 15, and then flows through the first chromatographic column 201, from the first chromatographic The gas flowing out of the column 201 enters the second connecting port and the third connecting port and flows through the second chromatographic column 202 through the third exhaust pipe 126 , and then the gas flowing out of the second chromatographic column 202 enters the detection unit 13 and is emptied. The first carrier gas flows through the first chromatographic column 201, the second chromatographic column 202, and the detection unit 13 in sequence, and then empties, so as to realize the cleaning of the system. After the cleaning is stable, the system reaches the preset level for the next step of analysis and detection. state. Through the structure of the ten-way valve 20 of the present invention, in the first state, the first chromatographic column 201, the second chromatographic column 202 and the detection unit 13 can be cleaned in series by the first carrier gas, the gas source is stable, and the efficiency is higher , which is conducive to obtaining more accurate detection results in the future.

At the same time, the second path of carrier gas provided by the carrier gas unit 16 is passed through the second inlet pipe 122 into the fourth connection port and the fifth connection port through the control unit 15 , and then evacuated through the first exhaust pipe 124 . Use the second carrier gas to keep cleaning the corresponding connection ports and pipelines to avoid contamination.

Afterwards, when the system reaches a predetermined steady 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 Figure 4, 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, and the seventh connection port communicates with the sixth connection port. The port is connected with the eighth connection port, and the ninth connection port is connected with the tenth connection port.

Then, through the sampling pump 18 and the gas sampling unit 11 , the sample gas is continuously passed into the third inlet pipe 123 , then enters the sixth connection port and the fifth connection port and is exhausted from the first exhaust pipe 124 . 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 and avoid data jumps that affect the detection accuracy.

At the same time, through the control unit 15, the first carrier gas provided by the carrier gas unit 16 is continuously introduced into the eighth connection port and the seventh connection port through the first air inlet pipe 121, and then enters the quantitative tube 203 to store therein the first state. The sample gas is pushed out of the quantitative tube 203, and then the sample gas flows into the tenth connecting port and the ninth connecting port and enters the first chromatographic column 201. The gas components firstly analyzed in the sample gas are directly emptied, and the separated gas is prepared as For the gas to be measured, the desorbed gas flowing out of the first chromatographic column 201 enters the second connection port and the first connection port, passes through the second exhaust pipe 125 and then is emptied. In this step of the present invention, the sample gas does not directly pass through the first chromatographic column 201 and the second chromatographic column 20 for serial analysis and detection, but a venting operation is performed before the detection, and the first chromatographic column 201 is used to carry out the sample gas A pre-separation is used to empty out the gas that has been analyzed first, so as to prevent this part of the gas from entering the detection unit 13 to generate shorter impurity "big bag peaks" and reduce the curve accuracy of the gas to be measured. After the emptying operation of the first chromatographic column 201, according to the characteristics of the first chromatographic column 201, the control unit 15 sets an appropriate time for state transition, and the gas to be analyzed and detected can be retained for the next step analyze.

At the same time, the second carrier gas provided by the carrier gas unit 16 is passed through the second inlet pipe 122 into the fourth connection port and the third connection port through the control unit 15, and then flows through the second chromatographic column through the third exhaust pipe 126 202, and then the gas flowing out from the second chromatographic column 202 enters the detection unit 13 and then is emptied. That is, while the first chromatographic column 201 is used to vent the gas desorbed earlier, the second chromatographic column 202 and the detection unit 13 are continuously purged and cleaned by the second carrier gas.

According to the characteristics of the first chromatographic column 201, the time for the first resolved gas to be emptied through the first chromatographic column 201 can be calculated or obtained experimentally. When the evacuation time for the first analyzed gas is reached, the control unit 15 automatically starts the state transition, That is, the ten-way valve 20 is adjusted from the second state to the third state through the control unit 15, that is, the ten-way valve 20 has a third state, and the connection relationship of the ten-way valve 20 in the third state is the same as that in the first state , as shown in Figure 3, similarly, at this moment, 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, and the sixth connection port communicates with the fifth connection port. The seventh connection port is connected, and the eighth connection port is connected to the ninth connection port.

In the third state, through the sampling pump 18 and the gas sampling unit 11, the collected sample gas is continuously passed into the third gas inlet pipe 123, then enters the sixth connection port and enters the quantitative tube 203 from the seventh connection port, from the quantitative The gas flowing out of the pipe 203 enters the tenth connecting port and the first connecting port and then is emptied through the second exhaust pipe 125; in this way, all the gas in the second state is discharged to be stored in the quantitative tube 203 for the next time Analyzed sample gas.

At the same time, the first path of carrier gas provided by the carrier gas unit 16 is continuously introduced into the eighth connection port and the ninth connection port through the first air inlet pipe 121 through the control unit 15, and then flows through the first chromatographic column 201, from the first chromatographic The gas flowing out of the column 201 pushes the gas to be tested separated in the second state into the second connection port and the third connection port, and then flows through the second chromatographic column 202 through the third exhaust pipe 126, and the second chromatographic column 202 makes the The components in the gas to be tested are analyzed and discharged at different speeds, and then the gas flowing out from the second chromatographic column 202 enters the detection unit 13 for detection and then is emptied; thereby completing a cycle of gas analysis in the third state; the detection unit 13 obtains The analysis result is further transmitted to the data acquisition and processing unit 14 through the circuit. Under this step, because the gas with shorter impurity "big bag peak" is discharged through the first chromatographic column 201 before, what is pushed to the second chromatographic column 202 by the carrier gas is the gas component that really needs to be analyzed and detected. The second chromatographic column 202 analyzes and discharges the gases of different components at different speeds, widens the interval between the peaks of the curves of different gas components, avoids the mutual covering and interference of adjacent peaks, and improves the detection of different components, especially trace components. , which improves the detection accuracy.

Simultaneously, the second path carrier gas provided by the carrier gas unit 16 is passed into the fourth connection port and the fifth connection port through the second air inlet pipe 122 by the control unit 15, and then is evacuated through the first exhaust pipe 124; All the gas in the second state is discharged, and the pipeline is cleaned by the carrier gas to prepare for the next gas analysis.

To sum up, the portable gas analyzer of the present invention provides an overall structure integrated in the box body, and each structure is stably connected as a whole in the box body, the structure is compact, easy to carry and transport, and is suitable for use in various field environments. Emergency gas analysis and testing. And the gas separation unit with an independent structure can easily form a highly integrated and interchangeable gas analyzer, reducing 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 uses the first chromatographic column to empty the miscellaneous peak gas analyzed earlier, which is beneficial to the improvement of the detection accuracy of the gas to be detected, and then uses the second chromatographic column to widen the peak distance of each component to improve the concentration of different components. Especially the detection degree of trace components improves the detection accuracy.

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. The 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 understand the present invention by considering the technical solutions involved in each embodiment as being able to be combined with each other to form different embodiments scope of protection.

The above descriptions are only illustrative specific implementations of the present invention, and are not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A portable gas analyzer 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), a carrier gas unit (16) and a calibration unit (17) are arranged in the box body (100); wherein the gas separation unit (12) is arranged in a separate separation box (120), and the separation box (120) is provided with three inlet pipes (121, 122, 123) and three outlet pipes (124, 125, 126) communicating the interior thereof.

2. The portable gas analyzer according to claim 1, wherein the three gas inlets (121, 122, 123) are a first gas inlet (121) and a second gas inlet (122) respectively communicating with the carrier gas unit (16), and a third gas inlet (123) communicating with the gas sample introduction unit (11) and the calibration unit (17).

3. The portable gas analyzer of claim 2, wherein the three exhaust pipes (124, 125, 126) are a first exhaust pipe (124) and a second exhaust pipe (125) for emptying, respectively, and a third exhaust pipe (126) communicating with the detection unit (13).

4. The portable gas analyzer according to claim 3, characterized in that the data acquisition and processing unit (14) is electrically connected to the detection unit (13), the data acquisition and processing unit (14) having a display screen (141) for displaying the detection results and at least one data output interface (142).

5. The portable gas analyzer of claim 4, wherein the carrier gas unit (16) comprises a carrier gas cylinder (161) built into the housing (100), the carrier gas cylinder (161) providing a first and a second path of carrier gas through the first and second inlet tubes (121, 122), respectively.

6. The portable gas analyzer according to claim 5, wherein the calibration unit (17) includes a calibration steel cylinder (171) and a dynamic calibration instrument (172) built in the case (100), the third gas inlet pipe (123) communicates the calibration steel cylinder (171) and the dynamic calibration instrument (172) through a three-way valve, and a sampling pump (18) is provided in the third gas inlet pipe (123).

7. The portable gas analyzer as set forth in claim 6, wherein 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; wherein the first connection port is in communication with the second exhaust pipe (125); the second connecting port is communicated with the ninth connecting port through a pipeline provided with a first chromatographic column (201); the third 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 third connecting port and the detection unit (13); the fourth connecting port is communicated with the second air inlet pipe (122); the fifth connection port is communicated with the first exhaust pipe (124); the sixth connecting port is communicated with the third air inlet pipe (123); the seventh connecting port is communicated with the tenth connecting port through a pipeline provided with a quantitative pipe (203); the eighth connecting port is communicated with the first air inlet pipe (121).

8. A method of operating a portable gas analyzer according to claim 7, the method 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 tenth connecting port and the first 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 eighth connecting port and the ninth connecting port through the first gas inlet pipe (121), then to flow through the first chromatographic column (201), the gas flowing out of the first chromatographic column (201) enters the second connecting port and the third connecting port, then flows through the second chromatographic column (202) through the third gas outlet pipe (126), and then the gas flowing out of the second chromatographic column (202) enters the detection unit (13) and is exhausted;

meanwhile, the second path of carrier gas provided by the carrier gas unit (16) is led into the fourth connecting port and the fifth connecting port through the second air inlet pipe (122) by the control unit (15) and then is exhausted through the first exhaust pipe (124).

9. The method of operation of claim 8, 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;

continuously introducing the collected sample gas into the third gas inlet pipe (123) through the sampling pump (18) and the gas sampling unit (11), and then entering the sixth connecting port and the fifth connecting port and being exhausted from the first exhaust pipe (124);

meanwhile, the control unit (15) enables the first path of carrier gas provided by the carrier gas unit (16) to be continuously introduced into the eighth connecting port and the seventh connecting port through the first gas inlet pipe (121), then the first path of carrier gas enters the quantitative pipe (203) to push the sample gas stored in the quantitative pipe (203) in the first state out of the quantitative pipe (203), then the sample gas flows into the tenth connecting port and the ninth connecting port to enter the first chromatographic column (201), gas components analyzed in the sample gas firstly are directly exhausted, the separated gas at the rear section is prepared to be used as gas to be detected, and the gas analyzed in the first path flowing out of the first chromatographic column (201) enters the second connecting port and the first connecting port and then is exhausted through the second exhaust pipe (125);

meanwhile, the control unit (15) enables the second path of carrier gas provided by the carrier gas unit (16) to be introduced into the fourth connecting port and the third connecting port through the second gas inlet pipe (122), then to flow through the second chromatographic column (202) through the third gas outlet pipe (126), and then the gas flowing out of the second chromatographic column (202) enters the detection unit (13) and is exhausted.

10. The method of operation of claim 9, further comprising the steps of:

adjusting the ten-way valve (20) from a second state to a third state through the control unit (15), wherein the connection relation of the ten-way valve (20) in the third state is the same as that in the first state, the first connection port is communicated with the tenth connection port, the second connection port is communicated with the third connection port, the fourth connection port is communicated with the fifth connection port, the sixth connection port is communicated with the seventh connection port, and the eighth connection port is communicated with the ninth connection port;

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) through the second gas exhaust pipe (125) after entering the tenth connecting port and the first connecting port; 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 flow into the eighth connection port and the ninth connection port through the first gas inlet pipe (121), then to flow through the first chromatographic column (201), the gas flowing out of the first chromatographic column (201) pushes the gas to be detected separated in the second state out to enter the second connection port and the third connection port, then to flow through the second chromatographic column (202) through the third gas outlet pipe (126), the components in the gas to be detected are 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 to be discharged; thus completing a cycle of gas analysis in the third state; the analysis result obtained by the detection unit (13) is further transmitted to the data acquisition and processing unit (14) through a circuit;

meanwhile, a second path of carrier gas provided by the carrier gas unit (16) is led into the fourth connecting port and the fifth connecting port through the second air inlet pipe (122) by the control unit (15), and then is exhausted through the first exhaust pipe (124); thereby, all the gas in the second state is discharged, and the piping is cleaned by the carrier gas to prepare for the next gas analysis.