VOCs component detection system and detection method

Abstract

The invention belongs to the technical field of VOCs detection, and particularly relates to a VOCs component detection system and method. Sample gas enters the enrichment unit from the sample gas port to be enriched; the first carrier gas passes through the enrichment unit after passing through the four-way valve, gas adsorbed in the enrichment unit is eluted, flows into the separation assembly to be separated, and then enters the PID detector to be detected and analyzed; after the analysis is finished, the carrier gas carrying atomized water and the dry carrier gas are sequentially used for back flushing, and then the next round of test can be carried out. According to the device, the low-heat-capacity chromatographic column and the high-sensitivity PID detector are adopted, through EPC control, the size and energy consumption of the device are effectively reduced, and the applicability of detecting broad-spectrum VOCs by using portable equipment is effectively improved; humidification reverse blowing and drying sweeping blowing are arranged, low-boiling-point species, oxygen-containing VOCs and nitrogen-containing VOCs which are difficult to remove traditionally can be effectively removed through humidification reverse blowing, background interference is reduced, and the VOCs detection effect is effectively improved.

Description

Technical Field

[0001] This application belongs to the technical field of VOCs detection, and particularly relates to a VOCs component detection system and a detection method. Background Art

[0002] Volatile organic compounds (VOCs) are an important trace component in ambient air. They contain a variety of important air pollutants, involve a variety of complex chemical structures and have a very low concentration in the atmosphere. Therefore, the accurate detection of VOCs components has high technical difficulty. At the same time, due to the complex sources of atmospheric VOCs, the concentrations, compositions and sources of VOCs at different sites vary greatly. Traditional large-scale equipment is huge in volume and often difficult to cover. Miniaturized VOCs component detection technology is an important factor in current air pollution control, environmental quality improvement and economic and social development.

[0003] Existing miniaturized VOCs monitoring equipment mainly focuses on the monitoring of the total amount of VOCs. The application of using small equipment to detect broad-spectrum VOCs is relatively limited. On the one hand, miniaturized equipment is limited by its volume and weight requirements, and has high requirements for structural design and component selection. On the other hand, miniaturized devices often face problems such as low detection limits, too much background interference, and difficulty in meeting the requirements of detection accuracy. There are often problems such as limited detected components (only a few species can be detected, low-concentration species are difficult to detect, and are easily interfered, etc.). Substances such as low-boiling-point species, oxygen-containing VOCs, and nitrogen-containing VOCs commonly found in ambient air are easily adsorbed and not easily removed on common pipeline equipment made of stainless steel, polytetrafluoroethylene and PEEK materials, resulting in monitoring residues and too high background noise problems, affecting the effective identification and analysis and detection of VOCs components.

[0004] A photoionization detector (PID) uses a high-energy ultraviolet light source to ionize gas molecules and generate an electric current signal. PID generally uses an ultraviolet light source, whose lifespan is much higher than that of PIDs with other ionization energy levels, and the range of VOCs components that can be identified is very wide. It is sensitive to a variety of VOCs components such as olefins, benzene series, aldehydes and ketones, and long-chain alkanes, and is more suitable for portable VOCs detection. However, the use of only PID has the problem of low selectivity. This application creatively uses the combination of PID and separation technology to achieve effective detection of broad-spectrum VOCs. Summary of the Invention

[0005] In view of the above problems existing in the prior art, this application provides a VOCs component detection system and a detection method, which can reduce background interference and improve the detection effect.

[0006] To achieve the above object, the technical solutions provided by this application are as follows:

[0007] In a first aspect, the present application provides a VOCs component detection system, including:

[0008] A twelve-way valve, which includes twelve valve ports, namely the first valve port, the second valve port, the third valve port, the fourth valve port, the fifth valve port, the sixth valve port, the seventh valve port, the eighth valve port, the ninth valve port, the tenth valve port, the eleventh valve port, and the twelfth valve port;

[0009] A sample gas port, which is connected to the second valve port of the twelve-way valve through a pipeline and is used for the entry of sample gas and the discharge of waste gas;

[0010] An enrichment unit for adsorbing VOCs components in the sample gas. One end of the enrichment unit is connected to the first valve port of the twelve-way valve, and the other end of the enrichment unit is provided with a three-way valve. The other two ends of the three-way valve are respectively connected to an air pump at one end and to the fourth valve port of the twelve-way valve through a pipeline at the other end;

[0011] A first carrier gas inlet pipeline for providing the first carrier gas for analysis and testing, which is connected to the fifth valve port of the twelve-way valve through a four-way valve;

[0012] A separation component for separating the VOCs components absorbed by the enrichment unit. The inlet end of the separation component is connected to the twelfth valve port of the twelve-way valve, and the outlet end of the separation component is connected to the eighth valve port of the twelve-way valve;

[0013] A PID detector for analyzing the concentration of VOCs components in the air. The inlet end of the PID detector is connected to the ninth valve port of the twelve-way valve;

[0014] A humidification backflush unit for providing a carrier gas carrying atomized water and a dry carrier gas for backflushing and controlling the switching of the backflush carrier gas between the carrier gas carrying atomized water and the dry carrier gas. The humidification backflush unit is connected to the seventh valve port of the twelve-way valve and is also connected to the third valve port of the twelve-way valve through the four-way valve;

[0015] The sixth valve port of the twelve-way valve is connected to the tenth valve port of the twelve-way valve through a pipeline, and the eleventh valve port of the twelve-way valve is connected to a waste gas discharge pipeline.

[0016] Optionally, the humidification backflush unit includes a second carrier gas inlet pipeline and an atomized water pipeline. The second carrier gas inlet pipeline and the atomized water pipeline are mixed in a certain proportion through a second flow control valve and then connected to the seventh valve port of the twelve-way valve and the four-way valve.

[0017] Optionally, the second flow control valve adopts EPC flow control.

[0018] Optionally, a first flow control valve is provided between the four-way valve and the seventh valve port of the twelve-way valve.

[0019] Optionally, the separation component includes a low heat capacity chromatographic column.

[0020] Optionally, the enrichment unit includes an enrichment tube filled with carbon black and carbon molecular sieve.

[0021] Optionally, when in the injection state, the first valve port of the twelve-way valve is communicated with the second valve port, the third valve port is communicated with the fourth valve port, the fifth valve port is communicated with the sixth valve port, the seventh valve port is communicated with the eighth valve port, the ninth valve port is communicated with the tenth valve port, and the eleventh valve port is communicated with the twelfth valve port;

[0022] When in the analysis state, the first valve port of the twelve-way valve is communicated with the twelfth valve port, the second valve port is communicated with the third valve port, the fourth valve port is communicated with the fifth valve port, the sixth valve port is communicated with the seventh valve port, the eighth valve port is communicated with the ninth valve port, and the tenth valve port is communicated with the eleventh valve port.

[0023] Optionally, the carrier gas in the first carrier gas inlet pipeline and the second carrier gas inlet pipeline includes one or more of nitrogen and helium.

[0024] In a second aspect, the present application further provides a method for detecting VOCs components, based on the VOCs components detection system described in the first aspect, including:

[0025] S1: Switch the twelve-way valve to the injection state, that is, the first valve port of the twelve-way valve is communicated with the twelfth valve port, the second valve port is communicated with the third valve port, the fourth valve port is communicated with the fifth valve port, the sixth valve port is communicated with the seventh valve port, the eighth valve port is communicated with the ninth valve port, and the tenth valve port is communicated with the eleventh valve port; switch the three-way valve to connect the enrichment unit with the air pump;

[0026] The sampled gas is extracted by the air pump and enters from the sampled gas port, and then enters the enrichment unit for enrichment after passing through the second valve port and the first valve port of the twelve-way valve in sequence;

[0027] S2: Switch the twelve-way valve to the analysis state, that is, the first valve port of the twelve-way valve is communicated with the twelfth valve port, the second valve port is communicated with the third valve port, the fourth valve port is communicated with the fifth valve port, the sixth valve port is communicated with the seventh valve port, the eighth valve port is communicated with the ninth valve port, and the tenth valve port is communicated with the eleventh valve port; switch the three-way valve to connect the enrichment unit with the fourth valve port of the twelve-way valve, and switch the four-way valve to connect the first carrier gas inlet pipeline with the fifth valve port of the twelve-way valve;

[0028] The first carrier gas enters after passing through the four-way valve, and then the first carrier gas sequentially passes through the fifth valve port, the fourth valve port of the twelve-way valve, and the three-way valve and then passes through the enrichment unit, eluting the adsorbed gas in the enrichment unit. After that, the gas flows into the separation component through the first valve port and the twelfth valve port of the twelve-way valve for separation. The separated components flow out through the eighth valve port and the ninth valve port of the twelve-way valve and enter the PID detector for detection and analysis to qualitatively and quantitatively detect the sample.

[0029] S3: Switch the twelve-way valve to the sampling state, switch the three-way valve so that the enrichment tube is connected to the fourth valve port of the twelve-way valve, and switch the four-way valve so that the humidification backflush unit is connected to the third valve port of the twelve-way valve.

[0030] The carrier gas with atomized water in the humidification backflush unit, on the one hand, passes through the three-way valve and then sequentially passes through the fourth valve port, the third valve port of the twelve-way valve, the three-way valve, the enrichment unit, and the first valve port and the second valve port of the twelve-way valve and is then discharged through the sample gas port; on the other hand, the carrier gas with atomized water in the humidification backflush unit passes through the seventh valve port and the eighth valve port of the twelve-way valve and then enters the separation unit, and then passes through the twelfth valve port and the eleventh valve port of the twelve-way valve and is discharged through the waste gas discharge pipeline.

[0031] Then switch the carrier gas with atomized water provided by the humidification backflush unit to dry carrier gas for drying.

[0032] Optionally, it further includes that in S1, switch the four-way valve so that the first carrier gas inlet pipeline is connected to the fifth valve port of the twelve-way valve.

[0033] The first carrier gas passes through the fifth valve port, the sixth valve port, the tenth valve port, and the ninth valve port of the twelve-way valve after passing through the four-way valve and then enters the PID detector, so that the gas inlet of the PID detector is stable when entering S2.

[0034] Compared with the prior art, the present application has at least the following beneficial effects:

[0035] The present application sets up humidification backflush and dry purge. Through humidification backflush, low-boiling species, oxygen-containing VOCs, and nitrogen-containing VOCs that are difficult to remove traditionally can be effectively removed, reducing background interference; then, backflushing with dry carrier gas can remove moisture and avoid the influence of humidity on the detection results. It effectively improves the detection effect of VOCs, also improves the accuracy and identification range of VOCs detection, and realizes the accurate monitoring of broad-spectrum VOCs components.

[0036] Adopting a low heat capacity chromatographic column and a highly sensitive PID detector, through EPC control, the volume of the device (the whole machine does not exceed 15 kg) and energy consumption are effectively reduced, and the applicability of using a portable device to detect broad-spectrum VOCs is effectively improved; through EPC flow control, the pressure in the fluid system is controlled by the strength of the electrical signal, enabling precise control of the flow rate and improving the repeatability and accuracy of qualitative and quantitative analysis. Brief Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 It is a system state diagram of a VOCs component detection system in the sample injection state in the embodiments of the present application;

[0039] Figure 2 It is a system state diagram of a VOCs component detection system in the analysis state in the embodiments of the present application;

[0040] Figure 3 It is a system state diagram of a VOCs component detection system in the backflush state in the embodiments of the present application;

[0041] Explanation of the Reference Numerals in the Drawings:

[0042] 1. First valve port; 2. Second valve port; 3. Third valve port; 4. Fourth valve port; 5. Fifth valve port; 6. Sixth valve port; 7. Seventh valve port; 8. Eighth valve port; 9. Ninth valve port; 10. Tenth valve port; 11. Eleventh valve port; 12. Twelfth valve port; 20. Twelve-way valve; 21. Sample gas port; 22. Enrichment tube; 23. Three-way valve; 24. Air pump; 25. First carrier gas inlet pipeline; 26. Four-way valve; 27. Low heat capacity chromatographic column; 28. PID detector; 29. Second carrier gas inlet pipeline; 30. Atomizing water pipeline; 31. Second flow control valve; 32. Exhaust gas discharge pipeline; 33. First flow control valve. Detailed Embodiments

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way limits the present application and its application or use.

[0044] Embodiment 1

[0045] As Figure 1 shown, a VOCs component detection system includes:

[0046] A twelve-way valve 20, which includes twelve valve ports, namely the first valve port 1, the second valve port 2, the third valve port 3, the fourth valve port 4, the fifth valve port 5, the sixth valve port 6, the seventh valve port 7, the eighth valve port 8, the ninth valve port 9, the tenth valve port 10, the eleventh valve port 11, and the twelfth valve port 12;

[0047] A sample gas port 21, which is connected to the second valve port 2 of the twelve-way valve 20 through a pipeline and is used for the entry of sample gas and the discharge of waste gas;

[0048] An enrichment unit, which is used to adsorb VOCs components in the sample gas. One end of the enrichment unit is connected to the first valve port 1 of the twelve-way valve 20, and a three-way valve 23 is provided at the other end of the enrichment unit. The other two ends of the three-way valve 23 are respectively connected to an air pump 24 at one end and to the fourth valve port 4 of the twelve-way valve 20 through a pipeline at the other end;

[0049] A first carrier gas inlet pipeline 25, which is used to provide the first carrier gas for analysis and testing. In this embodiment, nitrogen is used as the first carrier gas, and other inert gases such as helium can also be used. It is connected to the fifth valve port 5 of the twelve-way valve 20 through a four-way valve 26;

[0050] A separation component, which is used to separate the VOCs components absorbed by the enrichment unit. The inlet end of the separation component is connected to the twelfth valve port 12 of the twelve-way valve 20, and the outlet end of the separation component is connected to the eighth valve port 8 of the twelve-way valve 20;

[0051] A PID detector 28, which is used to analyze the concentration of VOCs components in the air. The inlet end of the PID detector 28 is connected to the ninth valve port 9 of the twelve-way valve 20;

[0052] A humidification backflush unit, which is used to provide the carrier gas carrying atomized water and the dry carrier gas for backflushing and control the switching of the backflush carrier gas between the carrier gas carrying atomized water and the dry carrier gas. The humidification backflush unit is connected to the seventh valve port 7 of the twelve-way valve 20 and is also connected to the third valve port 3 of the twelve-way valve 20 through the four-way valve 26.

[0053] In this embodiment, the humidification and back-blowing unit includes a second carrier gas inlet pipeline 29 and an atomizing water pipeline 30. The second carrier gas inlet pipeline 29 and the atomizing water pipeline 30 are mixed in a certain proportion through a second flow control valve 31 and then connected to the seventh valve port 7 of the twelve-way valve 20 and the four-way valve 26. The second carrier gas generally uses nitrogen or argon. The mixing ratio of the second carrier gas inlet pipeline 29 and the atomizing water pipeline 30 can be controlled through the second flow control valve 31. When the flow rate of the atomizing water pipeline 30 is controlled to be 0, dry carrier gas can be provided. In this embodiment, the atomizing water pipeline 30 is provided with atomized water vapor by an atomizing humidifier.

[0054] The sixth valve port 6 of the twelve-way valve 20 is connected to the tenth valve port 10 through a pipeline, and an exhaust gas discharge pipeline 32 is connected to the eleventh valve port 11 of the twelve-way valve 20.

[0055] When in the sample injection state, the first valve port 1 of the twelve-way valve 20 is communicated with the second valve port 2, the third valve port 3 is communicated with the fourth valve port 4, the fifth valve port 5 is communicated with the sixth valve port 6, the seventh valve port 7 is communicated with the eighth valve port 8, the ninth valve port 9 is communicated with the tenth valve port 10, and the eleventh valve port 11 is communicated with the twelfth valve port 12;

[0056] When in the analysis state, the first valve port 1 of the twelve-way valve 20 is communicated with the twelfth valve port 12, the second valve port 2 is communicated with the third valve port 3, the fourth valve port 4 is communicated with the fifth valve port 5, the sixth valve port 6 is communicated with the seventh valve port 7, the eighth valve port 8 is communicated with the ninth valve port 9, and the tenth valve port 10 is communicated with the eleventh valve port 11.

[0057] In this embodiment, a first flow control valve 33 is provided between the four-way valve 26 and the seventh valve port 7 of the twelve-way valve 20. The flow rate of the inflowing carrier gas can be adjusted through the first flow control valve 33.

[0058] In this embodiment, both the first flow control valve and the second flow control valve adopt EPC flow control.

[0059] In this embodiment, the separation component includes a low thermal mass chromatographic column 27. After separation through the low thermal mass chromatographic column 27 and then detection by a PID detector 28, multiple VOCs components can be identified simultaneously, avoiding the drawback of poor selectivity of the simple PID detector 28.

[0060] The enrichment unit includes an enrichment tube 22. The enrichment tube 22 is filled with carbon black and carbon molecular sieve, and the VOCs components are absorbed by the carbon black and carbon molecular sieve.

[0061] By combining the low heat capacity chromatographic column 27 with the PID detector 28, the detection accuracy is improved. The present application also provides humidification backflushing and drying sweep flushing. Through humidification backflushing, low-boiling species, oxygen-containing VOCs, and nitrogen-containing VOCs that are difficult to remove traditionally can be effectively removed, reducing background interference; then, moisture can be removed by drying carrier gas backflushing, avoiding the influence of humidity on the detection results. The detection effect of VOCs is effectively improved, and the accuracy and identification range of VOCs detection are also enhanced, realizing accurate monitoring of broad-spectrum VOCs components.

[0062] Example 2

[0063] This embodiment provides a method for detecting VOCs components. Based on the VOCs component detection system described in Embodiment 1, it includes:

[0064] S1: Sampling

[0065] Switch the twelve-way valve 20 to the sampling state, that is, the first valve port 1 of the twelve-way valve 20 is connected to the twelfth valve port 12, the second valve port 2 is connected to the third valve port 3, the fourth valve port 4 is connected to the fifth valve port 5, the sixth valve port 6 is connected to the seventh valve port 7, the eighth valve port 8 is connected to the ninth valve port 9, and the tenth valve port 10 is connected to the eleventh valve port 11; switch the three-way valve 23 to connect the enrichment tube 22 to the air pump 24;

[0066] The sampled gas is extracted by the air pump 24 and enters from the sampled gas port 21, and then enters the enrichment unit for enrichment after passing through the second valve port 2 and the first valve port 1 of the twelve-way valve 20 in sequence;

[0067] At the same time, switch the four-way valve 26 to connect the first carrier gas inlet pipeline 25 to the fifth valve port 5 of the twelve-way valve 20; the first carrier gas passes through the four-way valve 26 and then enters the PID detector 28 through the fifth valve port 5, the sixth valve port 6, the tenth valve port 10, and the ninth valve port 9 of the twelve-way valve 20, so that the intake of the PID detector 28 is stable when entering S2; Figure 1 It is the system state diagram in the sampling state.

[0068] S2: Analysis

[0069] Switch the twelve-way valve 20 to the analysis state, that is, the first valve port 1 of the twelve-way valve 20 is connected to the twelfth valve port 12, the second valve port 2 is connected to the third valve port 3, the fourth valve port 4 is connected to the fifth valve port 5, the sixth valve port 6 is connected to the seventh valve port 7, the eighth valve port 8 is connected to the ninth valve port 9, and the tenth valve port 10 is connected to the eleventh valve port 11; switch the three-way valve 23 to connect the enrichment tube 22 to the fourth valve port 4 of the twelve-way valve 20, and switch the four-way valve 26 to connect the first carrier gas inlet pipeline 25 to the fifth valve port 5 of the twelve-way valve 20;

[0070] Nitrogen enters through the first carrier gas inlet pipeline 25 and the four-way valve 26, and then successively passes through the fifth valve port 5, the fourth valve port 4 of the twelve-way valve 20, and the three-way valve 23, and then passes through the enrichment unit to elute the gas adsorbed in the enrichment tube 22. After that, the gas flows through the first valve port 1 and the twelfth valve port 12 of the twelve-way valve 20 and then enters the low thermal capacity chromatographic column 27 for separation. The separated components flow out through the eighth valve port 8 and the ninth valve port 9 of the twelve-way valve 20 and enter the PID detector 28 for detection and analysis to qualitatively and quantitatively detect the sample. Figure 2 It is the system state diagram in the analysis state.

[0071] S3: Backflush

[0072] Switch the twelve-way valve 20 to the injection state, switch the three-way valve 23 so that the enrichment tube 22 is connected to the fourth valve port 4 of the twelve-way valve 20, and switch the four-way valve 26 so that the humidification backflush unit is connected to the third valve port 3 of the twelve-way valve 20.

[0073] After controlling the second flow control valve 31 to regulate the flow rates of the atomizing water pipeline 30 and the second carrier gas inlet pipeline 29, the carrier gas carrying atomized water is obtained. On the one hand, the carrier gas carrying atomized water passes through the three-way valve 23 and then successively through the fourth valve port 4, the third valve port 3 of the twelve-way valve 20, the three-way valve 23, the enrichment unit, and the first valve port 1 and the second valve port 2 of the twelve-way valve 20 and is then discharged through the sample gas port 21. On the other hand, the carrier gas carrying atomized water passes through the seventh valve port 7 and the eighth valve port 8 of the twelve-way valve 20 and then enters the separation unit, and then passes through the twelfth valve port 12 and the eleventh valve port 11 of the twelve-way valve 20 and is discharged through the exhaust gas discharge pipeline 32.

[0074] Then control the second flow control valve 31 to switch the carrier gas to dry carrier gas for dry backflush. Figure 3 It is the system state diagram in the backflush link.

[0075] Through humidification backflush in this application, low-boiling species, oxygen-containing VOCs, and nitrogen-containing VOCs that are difficult to remove traditionally can be effectively removed, reducing background interference and the lowest limit value of the detection limit. Then, through dry carrier gas backflush, moisture can be removed to avoid the influence of humidity on the detection results and effectively improve the VOCs detection effect.

[0076] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood through specific situations.

[0077] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present application, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present application.

Claims

1. A VOCs component detection system, characterized in that, Comprising: A twelve-way valve, which includes twelve valve ports, namely the first valve port, the second valve port, the third valve port, the fourth valve port, the fifth valve port, the sixth valve port, the seventh valve port, the eighth valve port, the ninth valve port, the tenth valve port, the eleventh valve port, and the twelfth valve port; A sample gas port, which is connected to the second valve port of the twelve-way valve through a pipeline and is used for the entry of sample gas and the discharge of waste gas; An enrichment unit for adsorbing VOCs components in the sample gas. One end of the enrichment unit is connected to the first valve port of the twelve-way valve, and the other end of the enrichment unit is provided with a three-way valve. The other two ends of the three-way valve, one end is connected to an air pump, and the other end is connected to the fourth valve port of the twelve-way valve through a pipeline; A first carrier gas inlet pipeline for providing the first carrier gas for analysis and testing, which is connected to the fifth valve port of the twelve-way valve through a four-way valve; A separation component for separating the VOCs components absorbed by the enrichment unit. The inlet end of the separation component is connected to the twelfth valve port of the twelve-way valve, and the outlet end of the separation component is connected to the eighth valve port of the twelve-way valve; A PID detector for analyzing the concentration of VOCs components in the air. The inlet end of the PID detector is connected to the ninth valve port of the twelve-way valve; A humidification backflush unit for providing a carrier gas carrying atomized water and a dry carrier gas for backflushing and controlling the switching of the backflush carrier gas between the carrier gas carrying atomized water and the dry carrier gas. The humidification backflush unit is connected to the seventh valve port of the twelve-way valve and is connected to the third valve port of the twelve-way valve through the four-way valve; The sixth valve port of the twelve-way valve is connected to the tenth valve port through a pipeline, and the eleventh valve port of the twelve-way valve is connected to a waste gas discharge pipeline.

2. The VOCs component detection system according to claim 1, wherein The humidification backflush unit includes a second carrier gas inlet pipeline and an atomized water pipeline. The second carrier gas inlet pipeline and the atomized water pipeline are mixed in a certain proportion through a second flow control valve and then connected to the seventh valve port of the twelve-way valve and the four-way valve.

3. The VOCs component detection system according to claim 2, characterized in that, The second flow control valve adopts EPC flow control.

4. The VOCs component detection system according to claim 1, characterized in that, A first flow control valve is provided between the four-way valve and the seventh valve port of the twelve-way valve.

5. The VOCs component detection system according to claim 1, wherein The separation component includes a low thermal mass chromatographic column.

6. The VOCs component detection system according to claim 1, characterized in that, The enrichment unit includes an enrichment tube filled with carbon black and carbon molecular sieve.

7. The VOCs component detection system according to claim 1, wherein When in the sampling state, the first valve port of the twelve-way valve is communicated with the second valve port, the third valve port is communicated with the fourth valve port, the fifth valve port is communicated with the sixth valve port, the seventh valve port is communicated with the eighth valve port, the ninth valve port is communicated with the tenth valve port, and the eleventh valve port is communicated with the twelfth valve port; When in the analysis state, the first valve port of the twelve-way valve is communicated with the twelfth valve port, the second valve port is communicated with the third valve port, the fourth valve port is communicated with the fifth valve port, the sixth valve port is communicated with the seventh valve port, the eighth valve port is communicated with the ninth valve port, and the tenth valve port is communicated with the eleventh valve port.

8. The VOCs component detection system according to claim 1, wherein, The carrier gas in the first carrier gas inlet pipeline and the second carrier gas inlet pipeline includes one or more of nitrogen and helium.

9. A method for detecting VOCs components, characterized in that, Based on the VOCs component detection system according to any one of claims 1-8, comprising: S1: Switch the twelve-way valve to the sampling state, that is, the first valve port of the twelve-way valve is connected to the twelfth valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, the eighth valve port is connected to the ninth valve port, and the tenth valve port is connected to the eleventh valve port; switch the three-way valve to connect the enrichment unit to the air pump; The sampled gas is extracted by the air pump and enters from the sampled gas port, and then enters the enrichment unit for enrichment after passing through the second valve port and the first valve port of the twelve-way valve in sequence; S2: Switch the twelve-way valve to the analysis state, that is, the first valve port of the twelve-way valve is connected to the twelfth valve port, the second valve port is connected to the third valve port, the fourth valve port is connected to the fifth valve port, the sixth valve port is connected to the seventh valve port, the eighth valve port is connected to the ninth valve port, and the tenth valve port is connected to the eleventh valve port; switch the three-way valve to connect the enrichment unit to the fourth valve port of the twelve-way valve, and switch the four-way valve to connect the first carrier gas inlet pipeline to the fifth valve port of the twelve-way valve; The first carrier gas enters after passing through the four-way valve, and then the first carrier gas passes through the fifth valve port, the fourth valve port and the three-way valve of the twelve-way valve in sequence and then passes through the enrichment unit, eluting the adsorbed gas in the enrichment unit. After that, the gas flows into the separation component for separation after passing through the first valve port and the twelfth valve port of the twelve-way valve, and the separated components flow out through the eighth valve port and the ninth valve port of the twelve-way valve and enter the PID detector for detection and analysis to qualitatively and quantitatively detect the sample; S3: Switch the twelve-way valve to the sampling state, switch the three-way valve to connect the enrichment tube to the fourth valve port of the twelve-way valve, and switch the four-way valve to connect the humidification and backflush unit to the third valve port of the twelve-way valve; On the one hand, the carrier gas with atomized water in the humidification and backflush unit passes through the three-way valve and then passes through the fourth valve port, the third valve port, the three-way valve, the enrichment unit and the first valve port and the second valve port of the twelve-way valve in sequence and is discharged through the sampled gas port; on the other hand, the carrier gas with atomized water in the humidification and backflush unit passes through the seventh valve port and the eighth valve port of the twelve-way valve and then enters the separation unit, and then passes through the twelfth valve port and the eleventh valve port of the twelve-way valve and is discharged through the waste gas discharge pipeline; Then switch the carrier gas with atomized water provided by the humidification and backflush unit to dry carrier gas for drying.

10. The VOCs component detection method according to claim 9, wherein It also includes that in S1, switch the four-way valve to connect the first carrier gas inlet pipeline to the fifth valve port of the twelve-way valve; The first carrier gas passes through the fifth valve port, the sixth valve port, the tenth valve port and the ninth valve port of the twelve-way valve after passing through the four-way valve and then enters the PID detector, so that the gas inlet of the PID detector is stable when entering S2.

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