阅读说明：本技术 一种气敏-气相色谱多源感知和电子鼻仪器在线检测方法 (Gas-sensitive-gas chromatography multi-source sensing and electronic nose instrument on-line detection method ) 是由 高大启 盛明健 王泽建 万培耀 贺德贵 邢利民 于 2020-01-23 设计创作，主要内容包括：本发明提供一种气敏-气相色谱感知信息融合的电子鼻仪器在线检测方法,电子鼻仪器组成单元包括气敏传感器阵列、毛细管气相色谱柱、气体自动进样系统、计算机控制与分析诸模块,以及辅助气源。毛细管气相色谱柱、气敏传感器阵列和气体自动进样系统这3个模块分位于仪器右侧上、中和下方,计算机控制与分析模块位于仪器左侧。气体进样单周期T<Sub>0</Sub>＝300-600s,气敏传感器阵列和气相色谱柱二模块被测气体进样流量与累积进样量不相等,进样时间不同步,但计算机控制与分析模块对这两个模块感知信息选择与分析时间同步。电子鼻仪器可循环检测5个对象,循环检测周期最大为T＝5T<Sub>0</Sub>,实现多个生物发酵过程和恶臭污染点长期在线检测与智能分析。(The invention provides an electronic nose instrument on-line detection method for gas-sensitive-gas-chromatography sensing information fusion. The 3 modules of the capillary gas chromatographic column, the gas sensor array and the gas automatic sample feeding system are respectively positioned on, in and below the right side of the instrument, and the computer control and analysis module is positioned on the left side of the instrument. Gas sample introduction monocycle T 0 The sample introduction flow rate of the gas to be detected by the gas sensor array and the gas chromatographic column two modules is not equal to the accumulated sample introduction amount and the sample introduction time is asynchronous, but the computer control and analysis module is synchronous with the information selection and analysis time sensed by the two modules. The electronic nose instrument canCircularly detecting 5 objects with a maximum cycle detection period of T-5T 0 And long-term online detection and intelligent analysis of multiple biological fermentation processes and odor pollution points are realized.)

1. An electronic nose instrument on-line detection method with gas-sensitive/gas-chromatography perception information fused is characterized in that the electronic nose instrument comprises a gas-sensitive sensor array module I, a capillary gas chromatography column module II, a gas automatic sample feeding system module III, a computer control and analysis module IV and an auxiliary gas source V, and long-term circulation on-line detection and intelligent analysis of a plurality of biological fermentation processes or a plurality of odor pollution monitoring points are realized;

the gas sensor array module I comprises a gas sensor array I-1, a gas sensor array annular working cavity I-2, a resistance heating element I-3, a fan I-4, a heat insulation layer I-5 and a partition plate I-6 and is positioned in the right middle part of the electronic nose instrument;

the capillary gas chromatographic column module II comprises a capillary gas chromatographic column II-1, a detector II-2, an amplifier II-3, a recorder II-4, a sample inlet II-5, a resistance heating wire II-6, a fan II-7 and a heat insulation layer II-8 and is positioned at the upper right part of the electronic nose instrument;

the gas automatic sample injection system module III comprises: first to fifth two-position two-way electromagnetic valves III-1 to III-5, 5 first purifiers III-6, a first micro vacuum pump III-7, a first flowmeter III-8, a sixth two-position two-way electromagnetic valve III-9, a first throttle valve III-10, a two-position three-way electromagnetic valve III-11, a three-position four-way electromagnetic valve III-12, a second micro vacuum pump III-13, a seventh two-position two-way electromagnetic valve III-14, an eighth two-position two-way electromagnetic valve III-15, a pressure stabilizing valve III-16, a first pressure reducing valve III-17, a second throttle valve III-18, a second purifier III-19, a second pressure reducing valve III-20, a third purifier III-21, a third throttle valve III-22, a second flowmeter III-23, a fourth throttle valve III-24 and a fifth throttle valve III-25, is positioned at the right lower part of the electronic nose instrument;

the computer control and analysis module IV comprises a computer mainboard IV-1, an A/D data acquisition card IV-2, a driving and control circuit board IV-3, a 4-path precise direct current stabilized power supply IV-4, a display IV-5 and a WIFI module IV-6, and is positioned on the left side of the electronic nose instrument;

a biological fermentation process/fermenter or a foul odor contamination point is referred to as a detection point for short; the electronic nose instrument has a single sample introduction period T for the detected gas at a detection point₀300 + 600s, default T₀480 s; in gas sample introduction monocycle T₀In the method, a gas to be detected at a detection point is respectively pumped into a gas sensor array module I and a capillary gas chromatographic column module II by 2 micro vacuum pumps III-7 and III-13, the gas sensor array I-1 and the capillary gas chromatographic column II-1 generate sensitive responses, and an electronic nose instrument obtains 1 group of gas sensor array response curves and 1 gas chromatogram, which are gas-sensitive/gas chromatographic analog signals obtained by sensing a gas sample to be detected by the electronic nose instrument;

in gas sample introduction monocycle T₀In the method, the sample introduction time of the gas to be detected of the capillary gas chromatographic column module II is carried out earlier than that of the gas sensor array module I; t is₀The former is advanced by 400s compared with the latter when the time is 480 s; the sample introduction flow, sample introduction duration and accumulated sample introduction amount of the measured gas of the modules I and II are not equal, and the computer controls and analyzes the module IV to simultaneously select and analyze the information of the modules I and II;

in gas sample introduction monocycle T₀In the method, the electronic nose instrument senses the measured gas at a detection point to obtain an m-dimensional sensing vector x (tau) ∈ R^mReferred to as a sample; gas circulation of electronic nose instrument to 5 detection pointsThe cycle of loop sample introduction is T-5T₀Sequentially obtaining 5 samples, sequentially storing the samples in 5 corresponding data files of a computer control and analysis module IV, and sending the sample data to a cloud end and a specified fixed/mobile terminal through a WIFI routing module; if gas sample introduction is performed for a period T₀When the sampling period of the gas circulation of the 5 detection points is 480s, the sampling period is 2400s, and the detection is performed every 40min by one fermentation tank or one stink pollution observation point;

on-line/off-line detection and perception of conventional instruments such as an electronic nose instrument, a color/mass spectrum instrument and the like and professionals on a large number of biological fermentation processes or odor pollution points form odor big data X; in the learning stage, the computer controls and analyzes the machine learning model of the module IV to learn the data set X in an off-line manner so as to determine the structure and the parameters, and learns the near-term perception information of the gas-sensitive/gas chromatography in an on-line manner so as to finely adjust the parameters of the machine learning model; in a decision stage, a machine learning model determines a biological fermentation type and a malodor pollution type on line according to a current sensing vector x (tau) of a gas-sensitive/gas chromatography, and quantitatively predicts the concentration of main components of fermentation liquor or an odor concentration OU value and the concentrations of 8 malodor components specified by the national standard GB 14554.

2. The on-line detection method of the gas-sensitive/gas-chromatography sensing information fused electronic nose instrument as claimed in claim 1, wherein the gas-sensitive sensor array I-1 and the annular working cavity I-2 thereof are positioned in a 55 ± 0.1 ℃ incubator; in gas sample introduction monocycle T₀In the gas sensor array module I, the initial recovery T of the gas sensor array is sequentially carried out₀120s, accurate calibration of clean air for 40s, balance for 5s, headspace sample injection for measured gas for 60s, transition for 5s and flushing for 10s with environment purified air, wherein the 6 stages have the gas types and flow rates of ① environment purified air 6,500ml/min, ② clean air 1,000ml/min, ③ no-flow gas, ④ measured gas 1,000ml/min, ⑤ environment purified air 1,000ml/min and ⑥ environment purified air 6,500ml/min in sequence, and the transition mainly refers to the conversion from the measured gas to the environment purified air.

3. Gas/gas chromatograph according to claim 1The on-line detection method of the electronic nose instrument with the fusion of the perception information is characterized in that gas sample injection is carried out for a single period T₀[ T ] of₀-75s,T₀-15s]The time interval is at the stage of headspace sample injection of the gas to be detected of the gas sensor array module I, one of the 5 two-position two-way solenoid valves III-k (k is 1,2, …,5) from the first to the fifth is conducted, the three-position four-way solenoid valve III-12 is at the position of '0', the sixth and the seventh two-position two-way solenoid valves III-9 are disconnected from III-14, and the eighth two-position two-way solenoid valve III-15 is conducted; under the pumping action of a first micro vacuum pump III-7, the gas to be measured at one detection point sequentially flows through a k two-position two-way electromagnetic valve III-k (k is 1,2, …,5), an eighth two-position two-way electromagnetic valve III-15, a pressure stabilizing valve III-16, an annular working chamber I-2 and a gas sensor array I-1 inside the annular working chamber I-2, a first throttling valve III-10 and a first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 60 s; the gas sensor array I-1 thus generates a sensitive response to the gas to be measured and is stored in a temporary file in the computer control and analysis module IV.

4. The gas-sensitive/gas-chromatography sensing information fused electronic nose instrument on-line detection method as claimed in claim 1, wherein gas sample injection is performed in a single period T₀[ T ] of₀-120s,T₀-80s]The time interval is a clean air calibration stage of the gas sensor array module I, the three-position four-way electromagnetic valve III-12 is in the position of '1', the sixth, seventh and eighth two-position two-way electromagnetic valves III-9, III-14 and III-15 are all disconnected, clean air in the clean air bottle V-2 sequentially flows through the first pressure reducing valve III-17, the second throttling valve III-18, the second purifier III-19, the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1, the first throttling valve III-10 and the first flow meter III-8 in the annular working cavity I-2 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 40 s; during the period, the gas sensor array I-1 is accurately restored to the reference state under the action of clean air; as the eighth two-position two-way solenoid valve III-15 is disconnected, whether the 5 first to fifth two-position two-way solenoid valves III-1 to III-5 are connected or not does not influence the calibration of the gas sensor array I-1.

5. The on-line detection method of the gas-sensitive/gas-chromatography sensing information fused electronic nose instrument as claimed in claim 1, wherein the "environment purified air" is air obtained by dedusting, dehumidifying and sterilizing outdoor air where the electronic nose instrument is located, and is only used for preliminary recovery of the gas-sensitive sensor array I-1, flushing of the inner walls of the annular working cavity I-2 and related gas path pipelines, and taking away of accumulated heat of the gas-sensitive sensor array; in gas sample introduction monocycle T₀Is [0, T ]₀-120s]And [ T₀-10s,T₀]In the two time periods, the three-position four-way electromagnetic valve III-12 is in the position of 2', the sixth two-position two-way electromagnetic valve III-9 is switched on, the eighth two-position two-way electromagnetic valve III-15 is switched off, the environment purified air sequentially flows through the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1, the sixth two-position two-way electromagnetic valve III-9 and the first flow meter III-8 in the annular working cavity I-2 at the flow rate of 6,500ml/min, and is finally discharged to the outdoor for T continuously₀-110 s; during the period, the gas sensor array I-1 is preliminarily restored to the reference state under the action of the environment purified air; as the eighth two-position two-way solenoid valve III-15 is disconnected, whether the first to fifth 5 two-position two-way solenoid valves III-1 to III-5 are connected or not does not influence the initial recovery of the gas sensor array I-1.

6. The method as claimed in claim 1, wherein the size of the capillary chromatography column II-1 is determined by default to be a length L×, the inner diameter phi d ×, the film thickness 30m × phi 0.53mm × 0.25.25 μm, and the capillary chromatography column II-1 is located in a constant temperature chamber with a temperature of 250 plus or minus 0.1 ℃, and the capillary chromatography column II-1 is used for detecting the fusion of gas-sensitive/gas-sensitive information₀The capillary gas chromatographic column module II sequentially undergoes the headspace sample injection for 1s and the chromatographic separation for the gas to be detected T₀16s, and 15s of emptying and cleaning purging; h₂The clean air is combustion-supporting gas;

gas sample introduction monocycle T₀The first 1s is the tested gas headspace sampling stage of the capillary gas chromatographic column module II, the first to the fifthOne of the two-position two-way solenoid valves III-k (k is 1,2, …,5) is turned on, the two-position three-way solenoid valve III-11 is at the position "1", the seventh two-position two-way solenoid valve III-14 is turned on, and the eighth two-position two-way solenoid valve III-15 is turned off; at this time, the gas to be detected at the detection point k flows through one of the first to fifth two-position two-way electromagnetic valves III-k (k is 1,2, …,5), the seventh two-position two-way electromagnetic valve III-14, the two-position three-way electromagnetic valve III-11 and the fourth throttle valve III-24 in sequence under the suction action of the second micro vacuum pump III-13, and is mixed with the carrier gas H at the injection port II-5₂Mixed and therefore flowed into capillary gas chromatography column II-1 for 1 s; the default sample injection flow of the gas to be detected is 6ml/min, the default sample injection duration is 1s, and the default cumulative sample injection amount is 0.1 ml.

7. The gas-sensitive/gas-chromatography sensing information fused electronic nose instrument on-line detection method as claimed in claim 1, wherein gas sample injection is performed in a single period T₀Of [1s, T₀-10s]The time interval is the measured gas separation stage of the capillary gas chromatographic column module II, the two-position three-way electromagnetic valve III-11 is in the position of 2', the seventh two-position two-way electromagnetic valve III-14 is disconnected, and the measured gas from the detection point k is disconnected for a time of T₀-11 s; carrier gas H with certain pressure and flow rate of gas to be detected injected into sample inlet II-5 of gas chromatographic column module II₂Under the pushing action of the pressure sensor, separation is generated in a capillary gas chromatographic column II-1, a detector II-2 generates sensing accordingly, and after the sensing is amplified by an amplifier II-3, a recorder II-4 is used for recording [0, T ]₀-10s]Time interval, i.e. length T of chromatographic column II-1₀The perceived response of-10 s is recorded and stored in a temporary file of the computer control and analysis module IV.

8. The gas-sensitive/gas-chromatography sensing information fused electronic nose instrument on-line detection method as claimed in claim 1, wherein gas sample injection is performed in a single period T₀Last 10s of (i.e. [ T ]₀-10s,T₀]The time interval is the emptying, namely the cleaning and purging stage of the capillary gas chromatographic column II-1, and in the first to fifth 5 two-position two-way electromagnetic valves III-1 to III-5, the originally conducted one, namely III-k, is disconnectedTo turn off one of the other 4, i.e., III- (-k) conduction; the two-position three-way electromagnetic valve III-11 is at the position of 2, the seventh two-position two-way electromagnetic valve III-14 is conducted, and the eighth two-position two-way electromagnetic valve III-15 is disconnected; assuming that the two-position two-way solenoid valve III- (-k) is turned on (k is 1,2, …,5), the two-position two-way solenoid valve III- (-k), the seventh two-position two-way solenoid valve III-14 and the two-position three-way solenoid valve III-11 sequentially flow through the two-position two-way solenoid valve III- (-k), the seventh two-position two-way solenoid valve III-14 at a flow rate of 330ml/min under the suction action of the second micro vacuum pump III-13, and then are directly; the stage has the function of eliminating the residual smell from the kth detection point of the related pipeline in the current gas injection single period, gradually replacing the residual smell by the detected gas from the kth detection point, and preparing for detecting another biological fermentation process or odor pollution monitoring point in the next gas injection single period for 10 s.

Gas sample introduction monocycle T₀[ T ] of₀-10s,T₀]The time interval is simultaneously the time period for information selection and analysis, and the computer control and analysis module IV is controlled from [ T₀-75s,T₀-15s]Selection of a steady state peak value v in a time-sliced gas sensor array I-1 voltage response curve_gsi(τ) and the like; from [0, T₀-10s]Selecting the first 10 maximum chromatographic peaks v on the chromatogram of the time segment_gci(τ) a plurality of perceptual components; the method is the basis for analyzing the biological fermentation process or the odor pollution area by an electronic nose instrument; and the computer control and analysis module IV carries out odor type identification and intensity and main concentration index value quantitative prediction according to the perception vector x (tau).

9. The gas-sensitive/gas-chromatography sensing information fused electronic nose instrument on-line detection method as claimed in claim 1, wherein the method comprises a gas injection single period T₀In this case, when there is only one detection point, the gas circulation detection and analysis period is T ═ T₀(ii) a If k (═ 2,3,4,5) detection points are detected simultaneously, the cycle detection and analysis period is T ═ k × T₀(ii) a In the long-term circulation monitoring process, if one detection point exits, the circulation detection and analysis period is changed into T ═ k-1 × (T)₀(ii) a Similarly, during long-term cycling monitoring, if one is presentIf new detection points are added midway, the cycle detection and analysis period is changed into T ═ k +1 × (T)₀(ii) a And from the exit/entrance moment of one detection point, the corresponding data file recording period correspondingly changes.

10. The method for detecting the electronic nose instrument on line by fusing the gas-sensitive/gas-chromatographic sensing information of the claims 1 to 11 is characterized in that the electronic nose instrument carries out long-term circulating on-line detection and on-line analysis and prediction on a plurality of biological fermentation processes/odor pollution points, and comprises the following steps:

(1) starting up: preheating the instrument for 30 min;

modification of screen menu' gas sample introduction monocycle T₀"set, Default value T₀8 min; the gas circulation sampling period of the 5 detection points is T-5T₀；

The three-position four-way electromagnetic valve III-12 is in the position of 2, the sixth two-position two-way electromagnetic valve III-9 is conducted, and the eighth two-position two-way electromagnetic valve III-15 is disconnected; under the suction action of a first micro vacuum pump III-7, environment purified air sequentially flows through a three-position four-way electromagnetic valve III-12, a pressure stabilizing valve III-16, an annular working cavity I-2 and a gas sensor array I-1 thereof, a sixth two-position two-way electromagnetic valve III-9 and a first flow meter III-8 at the flow rate of 6,500ml/min, and is finally discharged to the outside; the internal temperature of the annular working cavity I-1 of the gas sensor array reaches 55 +/-0.1 ℃ which is constant;

the two-position three-way electromagnetic valve III-11 is at the position of 2', the seventh two-position two-way electromagnetic valve III-14 is disconnected, and the carrier gas H₂Under the pushing action of the capillary gas chromatographic column II-1, the capillary gas chromatographic column II-1 is gradually restored to a reference state, and the internal temperature of a chromatographic column box reaches constant 250 +/-0.1 ℃;

(2) beginning a gas circulation sample introduction period: clicking a 'detection point k on' option of a screen menu of a display IV-5, wherein k is 1,2, …,5, and continuously detecting by the electronic nose instrument for a long time until an operator clicks a 'detection point k off' option; the electronic nose instrument carries out cyclic detection on the 5 detection points in sequence, and the computer control and analysis module IV automatically generates 5 text files so as to store the sensing response data of the gas sensor array I-1 and the capillary gas chromatographic column module II to the 5 detection point gases;

(3) detecting the start of a gas sample introduction single period at a point k; by T₀As an example, 8 min:

(3.1) gas sensor array module I:

(3.1a) preliminary recovery: in gas sample introduction monocycle T₀In 0-360s, the three-position four-way electromagnetic valve III-12 is in the position of 2, the sixth two-position two-way electromagnetic valve III-9 is switched on, and the eighth two-position two-way electromagnetic valve III-15 is switched off; under the suction action of a first micro vacuum pump III-7, environment purified air sequentially flows through a three-position four-way electromagnetic valve III-12, a pressure stabilizing valve III-16, an annular working cavity I-2 and a gas sensor array I-1 thereof, a sixth two-position two-way electromagnetic valve III-9 and a first flow meter III-8 at the flow rate of 6,500ml/min, and is finally discharged to the outside; the gas sensor array I-1 is preliminarily restored to a reference state;

(3.1b) precise calibration: in gas sample introduction monocycle T₀400s in 360 th mode, the three-position four-way electromagnetic valve III-12 is in the position of 1', the sixth, seventh and eighth two-position two-way electromagnetic valves III-9, III-14 and III-15 are all disconnected, clean air sequentially flows through the first pressure reducing valve III-17, the second throttle valve III-18, the second purifier III-19, the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working chamber I-2 and the gas sensor array I-1 in the annular working chamber I-2, the first throttle valve III-10 and the first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 40 s; the gas sensor array I-1 is thus restored accurately to the reference state;

(3.1c) balance: in gas sample introduction monocycle T₀400 th-405 th s, the three-position four-way solenoid valve III-12 is in the position of 0, the sixth and eighth two-position two-way solenoid valves III-9 and III-15 are disconnected, no gas flows in the annular working cavity I-2 of the gas sensor array, and the operation lasts for 5 s;

(3.1d) headspace sampling: in gas sample introduction monocycle T₀405-; in the first micro-vacuum pump III-7Under the pumping action, the gas to be detected at one detection point sequentially flows through a two-position two-way solenoid valve III-k (k is 1,2, …,5), an eighth two-position two-way solenoid valve III-15, a pressure stabilizing valve III-16, an annular working cavity I-2 and a gas sensor array I-1 thereof, a first throttle valve III-10 and a first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 60 s; the sensitive response generated by the gas sensor array I-1 is stored in a temporary file corresponding to the computer control and analysis module IV;

(3.1e) transition: in gas sample introduction monocycle T₀465 th and 470s, the three-position four-way solenoid valve III-12 is in the position of '2', the eighth two-position two-way solenoid valve III-15 is disconnected, and the sixth and seventh two-position two-way solenoid valves III-9 and III-14 are kept disconnected; under the suction action of a first micro vacuum pump III-7, environment purified air sequentially flows through a three-position four-way electromagnetic valve III-12, a pressure stabilizing valve III-16, an annular working cavity I-2 and a gas sensor array I-1 thereof, a sixth two-position two-way electromagnetic valve III-9 and a first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside;

(3.1f) cleaning: in gas sample introduction monocycle T₀470-480s, compared with the "transition" stage, the positions of the other valves are the same except that the sixth two-position two-way solenoid valve III-9 is changed from "off" to "on"; the ambient purge air flow rate was thus changed from "1,000 ml/min" to "6,500 ml/min"; the valve position and the working state of the stage are completely the same and are connected with the valve position and the working state of the next single-cycle initial recovery stage to be started;

(3.2) capillary gas chromatography column II module:

(3.2a) headspace sampling: in gas sample introduction monocycle T₀0-1s, one of the 5 two-position two-way electromagnetic valves III-k (k is 1,2, …,5) is turned on, the two-position three-way electromagnetic valve III-11 is at the position "1", the seventh two-position two-way electromagnetic valve III-14 is turned on, and the eighth two-position two-way electromagnetic valve III-15 is turned off; under the suction action of the second micro vacuum pump III-13, the gas to be detected at the detection point k sequentially flows through one of the first to fifth two-position two-way electromagnetic valves III-k (k is 1,2, …,5), the seventh two-position two-way electromagnetic valve III-14, the two-position three-way electromagnetic valve III-11 and the fourth throttle valve III-24, and is at the sample inlet II-5With a carrier gas H₂Mixing, flowing into capillary gas chromatographic column II-1 for 1 s;

(3.2b) chromatographic separation: in gas sample introduction monocycle T₀1-470s, the two-position three-way electromagnetic valve III-11 is in the position of 2, and the seventh two-position two-way electromagnetic valve III-14 is disconnected; carrier gas H of measured gas under certain pressure and flow₂Under the driving action of the sensor, the sensor II-2 generates sensing response in the capillary gas chromatographic column II-1, and after the sensing response is amplified by the amplifier II-3, the recorder II-4 will generate 0,470s]Recording the perception response of the interval duration 470s to form a semi-separation chromatographic peak map, and storing the semi-separation chromatographic peak map in a temporary file of the computer control and analysis module IV;

(3.3) information selection and analysis: in gas sample introduction monocycle T₀470-480s, the computer control and analysis module IV from 405s,465s]Selecting steady state peak value v in each gas sensor voltage response curve of time period_gsi(τ) and the like; from [0,470s]Selecting 10 maximum chromatographic peaks v on the chromatogram of the time segment_gci(τ) and the like; in gas sample introduction monocycle T₀In the system, the computer control and analysis module IV obtains 1 m-dimensional sensing vector x (tau) ∈ R from the sensing information of the gas sensor array I module and the capillary chromatographic column module II^m(ii) a Then, the machine learning model carries out odor type identification and intensity and main component quantitative prediction according to the perception vector x (tau), and a monitor displays monitoring and prediction results and transmits the results to a central control room and a plurality of fixed/mobile terminals through the Internet;

(3.4) ending the detection point k and starting the next detection point;

one of the first to fifth 5 two-position two-way solenoid valves III-k (k is 1,2, …,5) is turned off from the original on state, and one of the first to fifth two-position two-way solenoid valves corresponding to the next detection point is turned on;

(4) and (5) repeating the steps (3.1) to (3.4), and realizing the circulation online detection, identification and multi-item concentration index value quantitative prediction of the detected gas at 1-5 detection points by the electronic nose instrument.

Technical Field

The invention discloses an online detection method of an electronic nose instrument with a gas sensor array and a capillary gas chromatographic column fused, which aims at the requirements of long-term automatic cycle continuous online state monitoring and analysis in the odor change process represented by biological fermentation and environmental odor pollution, relates to the technical fields of artificial intelligence, computers, analytical chemistry, environmental protection, bioengineering and the like, and mainly solves the problems of insufficient sensitivity and poor selectivity of the gas sensor array, the problem of fusion of a gas sensitive and gas chromatographic structure and sensing information and the problem of online detection of the electronic nose instrument.

Background

The olfaction simulation-electronic nose method uses a plurality of gas sensitive elements with overlapped performance to form an array to realize the rapid detection of the odor, and uses a machine learning method to perform qualitative and quantitative analysis of the odor. The electronic nose instrument is concerned about due to the characteristics of high speed, non-contact, simple and convenient operation and the like, and the online odor detection and analysis technology becomes a core application technology in the industries of environmental protection, bioengineering, food and the like. The current situation of electronic nose theory and technical research is that the sensitivity of the gas sensor reaches 10^-7(V/V), i.e., on the order of 0.1ppm, but poor selectivity, resulting in poor electronic nose instrument stability, linearity, and qualitative and quantitative capability; products such as the fermentation electronic nose and the like belong to the international blank. Under the background of important requirements, the electronic nose technology is listed in the department of science and technology "863", science and technology support and key research and development plans for many times.

The premise of real-time (real-time) prediction and control of biological fermentation and environmental odor pollution processes is online (online) detection and analysis of a plurality of process parameters. The environmental odor pollution time span is months after years; the biological fermentation process is short for 1-2 days and long for tens of days (such as beer fermentation). The shape of malodorous pollution and the change of the state of the biological fermentation process is slightly exaggerated by 'instantaneous change', but the detection and analysis period in the unit of 'hour' is definitely too long. It is considered that the state of the object to be detected does not change greatly within 1min, that is, the detection period is less than 1 min; in turn, the biological fermentation or the foul smell pollution state can be changed greatly within 1 hour, and the timing manual work with the period of 1 hour or moreSampling "intermittent" testing is not considered appropriate as "on-line" testing. Therefore, the on-line detection and analysis period of the electronic nose instrument to a single odor monitoring point or a single biological fermentation process (fermentation tank) is not suitable to exceed T₀10min, circulating on-line monitoring and analyzing period T n T of multiple fermentation tanks or multiple stink monitoring points₀It is not advisable to exceed 1 hour, so it is reasonable to determine whether a detection and analysis method is "on-line".

One of the main development trends of the electronic nose technology is that an array is formed by a plurality of gas sensitive devices with necessary sensitivity, and the qualitative and quantitative capability of complex odor is improved by emphatically utilizing big data and an artificial intelligence technology, so that the odor type identification and the quantitative prediction of the intensity and key components are realized. The long-term continuous online detection and analysis is a main working mode of the electronic nose, and is mainly oriented to automatic continuous online monitoring, online qualitative analysis and online prediction of the concentration of a plurality of main components of the process of application objects such as biological fermentation, environmental odor pollution and the like. The method is characterized in that qualitative and quantitative analysis is carried out on the fermentation tail gas/malodorous gas by the electronic nose instrument through sensing the fermentation tail gas/malodorous gas once and again, the source of the detected gas is abundant, the gas sampling period is fixed (for example, 5min), the gas extraction flow and the extraction duration are fixed, the process is repeated in cycles, and a complete biological fermentation and malodorous pollution detection process usually lasts for days, weeks, months or even years.

The basic premise of the electronic nose instrument adopting a continuous on-line detection and analysis working mode is that the core of the electronic nose instrument, namely the gas sensor array, has remarkable sensing capability on a detected object. From the application perspective, the performance indexes that the gas sensor should achieve include: high sensitivity (above ppm level), fast response speed (within 1 min), stable working state, high commercialization degree, long service life (3-5 years), small size and good selectivity.

Document [1 ]]The sensing performance of 6 common gas sensor types is listed according to different sensitive materials and working principles: metal Oxide Semiconductor (MOS) type, Electrochemical (EC) type, Conductive Polymer (CP) type, quartz microbalance (Q) typeMB) type, Surface Acoustic Wave (SAW) type, and Photo Ion (PID) type. Compared with MOS type, EC type gas sensor has better selectivity, but has much larger size, shorter service life by more than 1 year and lower sensitivity by more than one order of magnitude. Also, compared with the MOS type, the PID type sensor is large in size, narrow in sensing range, high in price, and has a lifetime of only about half a year. Moreover, EC-type and PID-type gas sensors are only suitable for detection of malodorous pollutants. The sensitivity of the QMB and SAW gas sensitive elements is lower than that of the MOS gas sensitive elements by more than 1 order of magnitude, sensitive film materials are to be further developed, and the size is to be further reduced. Combining various factors, as SnO₂The representative MOS type gas sensor is most suitable for being used as a sensing element of an electronic nose instrument.

It is necessary to point out that the sensing capability of the single type gas sensor made of the 6 sensitive materials and the array thereof is very limited and is not enough to meet the online detection requirements of application objects such as biological fermentation, odor pollution and the like, a large number of experiments indicate that ① even the MOS gas sensor with the highest sensitivity is not sensitive to phenylacetic acid which is a penicillin fermentation precursor, ② the existing electronic nose is not sensitive to odor collected by a certain pig farm^-7Of the order of (V/V), which is only the case for certain MOS-type sensors for certain odour components, and is not a general phenomenon. The most typical examples are electronic nose instruments for malodor contaminant detection and prediction of the main malodor compound concentration indicators. Specific criteria specified in GB14554 include ammonia NH₃Hydrogen sulfide H₂S, carbon disulfide CS₂Trimethylamine C₃H₉N, methyl mercaptan CH₄S, dimethyl sulfide C₂H₆S, dimethyldisulfide C₂H₆S₂Styrene C₈H₈The total concentration index value of 8 specific compounds is added with an odor concentration OU (odor unit) value, which is called 8+1 odor pollutant concentration control index value for short. Now, for CS₂、C₃H₉N、CH₄S、C₂H₆S、C₂H₆S₂、C₈H₈The 6 malodorous organic compounds are all sensitive and selectedA gas sensor array with good selectivity does not exist, and is difficult to develop in a short time. That is, it is difficult to realize the online detection and prediction of the 8+1 odor pollution index values by the sensor array of the above 6 gas sensitive material types.

A large number of redundant gas sensors form an array to detect the passage of a large number of odors; on one hand, the instrument structure is very complex, and on the other hand, the sensitivity of the gas sensor is not enough and the overlapping sensing range is limited [1 ]]The commercial product of chromatographic electronic noses has emerged, for example from the company Heracleis fast gas electronic nose, α MOS, France₀The gas of 5-8min is detected and analyzed at one time, is only suitable for on-site detection at any time, and is not suitable for long-term continuous on-line detection.

The gas chromatography has good selectivity, and the MOS gas sensor has poor selectivity. However, this difference is only relative, and the "qualitative ability" of gas chromatography on unknown samples is still "weak". That is, without an internal/external standard sample spectrum, the spectrum obtained by only one measurement cannot determine the components and compositions of the unknown sample at all. The second drawback of gas chromatography is that the column "selectivity" is not universal. A particular column is sensitive to a particular sample only under particular conditions, i.e. a particular column can only detect a particular range of a particular sample. When the sampling condition, the testing condition or the self parameter of the chromatographic column changes, the chromatographic sensing parameter of the specific sample changes along with the change.

It must be noted that the heart of gas chromatography is separation, not detection. Effective methods for increasing the degree of chromatographic separation include: (1) properly increasing the column length; (2) the sample introduction amount and the sample introduction time are properly reduced; (3) properly reducing the carrier gas flow rate; (4) properly reducing the temperature of the chromatographic column; (5) the temperature of the vaporization chamber is appropriately increased. It must be clear that a suitable increase in the temperature of the column and/or a suitable increase in the flow rate of the carrier gas is advantageous for reducing the retention time. Therefore, improving the degree of chromatographic separation and shortening the retention time are sometimes contradictory.

In order to improve the detection speed of the gas chromatography, a capillary column with a larger inner diameter can be selected, for example, the diameter is 0.53mm, the column length can be 30m, and a GC constant-temperature working chamber is designed and manufactured; an operator can conveniently replace and install the capillary column and the whole module; the hydrogen is used as carrier gas and fuel gas, and the temperature programming, sample introduction of the gas to be detected and the carrier gas pushing process are precisely controlled. At T₀In a period less than or equal to 10min, the sample injection flow of the detected gas can be 1.0-15ml/min, and the sample injection time can be 0.5-1.5 sec. At this time, we get a frame of T₀Semi-isolated multimodal plots of finite duration ≦ 10 min.

Both single columns and single type sensitive material gas sensor arrays are limited in terms of sensing range. Gas chromatography is difficult to analyze inorganic substances and easily decomposed high-boiling organic substances, difficult to characterize unknown substances, and is not suitable for analyzing single compounds with strong polarity or complex compounds with large polarity difference and some compounds without carbon. For example, a gas chromatograph using a Hydrogen Flame Ionization Detector (FID) cannot effectively detect inorganic compounds. The odor is a mixture of tens, hundreds, or even thousands of compounds, all of which have a molecular weight of less than 300 daltons. Retention time is an important qualitative analytical parameter for chromatography, whereas the chromatographic retention time for 8 malodorous compounds specified in GB14554 is mostly less than 8 min. The invention provides a driving factor of an electronic nose instrument on-line detection and analysis method for fusing a gas sensor array and a capillary gas chromatographic column.

Why are the gas sensor array fused with the capillary gas chromatography column? One of the reasons is that the gas sensor has poor selectivity and poor sensitivity to some compounds. For example, for some non-reducing/oxidizing inorganic compounds, phenylacetic acid which is a penicillin fermentation precursor, and the like, the online quantitative prediction of 8+1 odor pollution indexes specified by GB14554 cannot be realized only by the existing gas sensor array. The second reason is that gas chromatography has poor linearity and limited selectivity of a single chromatographic column. For example, gas chromatography can only detect samples with good thermal stability; according to incomplete statistics, the company Agilent offers thousands of ready-to-use chromatography columns. The fact that "column selection and replacement operations" indicate that the detection range of a single column is limited.

A typical example is GB14554 which states: NH (NH)₃And CS₂The concentration of these 2 malodorous contaminants was determined spectrophotometrically, H₂S、C₃H₉N、CH₄S、C₂H₆S、C₂H₆S₂、C₈H₈The concentrations of the 6 kinds of malodorous pollutants are detected by gas chromatography. It is worth noting that 3 national standards GB/T14676-14678 respectively specify the gas chromatography detection method of the latter 6 malodorous pollutants, wherein the detector, the chromatographic column and the working conditions are different from each other. We found that these several national standards specify that 6 malodorous compounds were measured separately using 2 different size packed columns. That is, a single column cannot detect 6 malodorous compounds as specified in GB14554 simultaneously. In short, many factors such as the material of the chromatographic column itself, the stationary phase, the inner diameter, the membrane thickness, the column length, the polarity and the non-polarity of the sample to be detected, etc. need to be considered for selecting the chromatographic column.

The gas sensor has the advantages of high response speed, low requirement on working conditions, poor selectivity and unsatisfactory sensitivity. The GC method has the advantages of high sensitivity and good selectivity, and has the disadvantages of long separation time, namely detection period, complex instrument structure and harsh working conditions, and the existing method is completely not suitable for long-term online detection. The gas sensor array and the capillary gas chromatographic column form a sharp contrast, and the fusion of the two can achieve the effect of making up for the deficiency, and bring out the best in each other. In order to realize the on-line sensing of a fermentation process and a broad range of odor pollutants, the problem to be solved is how to combine a gas sensor array and a chromatographic column, complement the advantages and realize long-term circulating on-line detection with a single period of about 5-10 min.

In order to realize the online detection and analysis method of the electronic nose instrument fused by the gas sensor array and the capillary gas chromatographic column, the following technical problems of odor perception theory and analysis need to be solved:

(A) gas sensor array and gas chromatographic column combination and electronic nose instrument on-line sensing ability problem

The odor is characterized in that (1) the components are numerous and change all the time. Taking malodorous pollutants as an example, the odor component can remove H₂S、NH₃、SO₂And the like, and most are organic substances, i.e., "volatile organic compounds". (2) Some components have low olfactory threshold value, but have high contribution degree to the odor intensity; and vice versa. One dilemma encountered in practical application of the electronic nose is that some components have small contribution degree to the odor intensity, and the gas sensor is very sensitive; and vice versa. The gas sensor is used for on-line detection of odor, and has performance indexes including: the sensitivity is high enough, the response speed is fast enough, the working state is stable, the commercialization degree is high, the service life is long, the size is small, and the selectivity is good. The characteristics of different gas sensors are deeply understood, and the small gas sensor array module is designed, so that the problems of poor stability, noise elimination, temperature and humidity compensation, convenience in replacement and the like are effectively solved.

(B) Modularization of key components such as gas sensor array and the like and integration and automation of electronic nose instrument

The odor components are numerous and the environment is variable, and it is uneconomical or even impractical to attempt to use redundant gas sensors to form arrays to detect all odors. We have previously indicated that the sensing range of both single column and single type gas sensor arrays is limited. Therefore, the gas sensor array and the gas chromatographic column optimization and fusion method are provided, and the odor sensing system, the gas automatic sample introduction system, the driving and control circuit, the computer and the like are modularized and integrated in a test box, so that a multipoint centralized electronic nose instrument with small size, light weight and simple and convenient operation is developed; the working state of each part in the instrument is precisely controlled, the working condition in the instrument is optimized, and the internal 'invariable' is used for responding to the external 'universal variation'. Ideally, one electronic nose instrument can simultaneously perform online detection on a plurality of fermentation tanks or a plurality of odor pollution observation points in a specific area for 24 hours every day by taking the year and the month as a unit, namely fixed point detection and movable point detection; the method is characterized in that real-time online analysis and prediction of odor intensity and main component concentration are achieved through a simple and effective machine learning model and algorithm, detection data and analysis results are transmitted to a monitoring center and various terminals through a cloud end in real time through a WIFI technology, and remote monitoring of a specific area based on the Internet is achieved.

(C) On-line analysis capability and intelligentization problem of odor electronic nose instrument based on big data and machine learning

Human society is in the era of big data and artificial intelligence. Health big data, financial big data, traffic big data, business big data, genetic big data, etc. are deeply changing people's life and working patterns. In China, the agenda has been proposed for big data of ecological environment, and the environmental protection departments of government are in great effort.

There is no multisource perception data generated by on-line testing of a large amount of odors, no component detection data of conventional instruments such as olfactory discrimination data and color/mass spectra, and it is unrealistic to attempt to estimate the intensity of complex odors and the concentration of various components on line simply by a single type gas sensor array, a single gas chromatographic column and a single machine learning model. Although many electronic noses do so today, the contribution of the resulting test data is quite limited and the results obtained are therefore not reliable.

Due to odor complexity and environmental variability, small data is not sufficient to train efficient machine learning models to identify multiple odor types and quantitatively predict complex odor components. The odor big data is established on the basis of detection data of conventional instruments such as gas-sensitive/chromatographic multi-source perception data, olfactory identification data, color/mass spectrum and the like. With the big data, the machine learning method can identify the odor type and quantitatively predict the concentration of a plurality of components through data mining according to the current perception information. The big data and the on-line prediction of the odor components are two contradictory aspects, and the effective solution is to deeply research and adopt a machine learning model and an algorithm which are as simple and effective as possible to realize the type recognition of the odor and the real-time quantitative prediction of the odor intensity and the concentration of various main components.

Reference documents:

[1]P.Boeker,On'Electronic Nose'methodology,Sensors&Actuators B-Chemical,2014,204:2–17.

disclosure of Invention

The invention discloses an electronic nose instrument and an online detection and analysis method for a stink pollution/biological fermentation process on the basis of the existing invention patents of ' a stink gas multipoint centralized online monitoring and analysis system and method ' (see application number: 2018104716131) ', ' a big data driven stink gas multipoint centralized electronic nose instrument online analysis method ' (see application number: 2018104717083) ', and ' a multichannel integrated smell simulation instrument and biological fermentation process online analysis method ' (see application number: 201310405315.X) ', so as to solve the problems of long-term online monitoring of a plurality of fermentation processes or a plurality of stink monitoring points, identification of fermentation and stink pollution types, and online quantitative prediction of a stink intensity qualitative index and a plurality of concentration control indexes.

In order to achieve the above purpose, the invention provides the following technical scheme:

in the gas-sensitive/gas-chromatographic sensing fused online detection method of the electronic nose instrument, the electronic nose instrument comprises a gas-sensitive sensor array module I, a capillary gas chromatographic column module II, a gas automatic sampling system module III, a computer control and analysis module IV and an auxiliary gas source V, and long-term circulating online detection and intelligent analysis of a plurality of biological fermentation processes or a plurality of malodorous pollution monitoring points are realized.

The gas sensor array module I comprises a gas sensor array I-1, a gas sensor array annular working cavity I-2, a resistance heating element I-3, a fan I-4, a heat insulation layer I-5 and a partition plate I-6 and is positioned in the right middle of the electronic nose instrument.

The capillary gas chromatographic column module II comprises a capillary gas chromatographic column II-1, a detector II-2, an amplifier II-3, a recorder II-4, a sample inlet II-5, a resistance heating wire II-6, a fan II-7 and a heat insulation layer II-8 and is positioned at the upper right part of the electronic nose instrument.

The gas automatic sample introduction system module III comprises: first to fifth two-position two-way electromagnetic valves III-1 to III-5, 5 first purifiers III-6, a first micro vacuum pump III-7, a first flowmeter III-8, a sixth two-position two-way electromagnetic valve III-9, a first throttle valve III-10, a two-position three-way electromagnetic valve III-11, a three-position four-way electromagnetic valve III-12, a second micro vacuum pump III-13, a seventh two-position two-way electromagnetic valve III-14, an eighth two-position two-way electromagnetic valve III-15, a pressure stabilizing valve III-16, a first pressure reducing valve III-17, a second throttle valve III-18, a second purifier III-19, a second pressure reducing valve III-20, a third purifier III-21, a third throttle valve III-22, a second flowmeter III-23, a fourth throttle valve III-24 and a fifth throttle valve III-25, is positioned at the right lower part of the electronic nose instrument.

The computer control and analysis module IV comprises a computer mainboard IV-1, an A/D data acquisition card IV-2, a drive and control circuit board IV-3, a 4-path precise direct current stabilized power supply IV-4, a display IV-5 and a WIFI module IV-6, and is positioned on the left side of the electronic nose instrument.

A biological fermentation process/fermenter or a foul odor contamination point is referred to as a detection point for short; the electronic nose instrument has a single sample introduction period T for the detected gas at a detection point₀300 + 600s, default T₀480 s. In a single period T₀In the device, the gas to be detected at a detection point is respectively pumped into a gas sensor array module I and a capillary gas chromatographic column module II by 2 micro vacuum pumps III-7 and III-13, the gas sensor array I-1 and the capillary gas chromatographic column II-1 generate sensitive responses, and an electronic nose instrument obtains 1 group of gas sensor array response curves and 1 gas chromatogram, which are gas-sensitive/gas chromatographic analog signals obtained by sensing a gas sample to be detected by the electronic nose instrument.

In gas sample introduction monocycle T₀The gas to be measured is injected into the capillary gas chromatographic column module II earlier than the gas sensor array module I, e.g. T₀The former is advanced by 400s compared with the latter when the time is 480 s; the sample introduction flow, sample introduction duration and accumulated sample introduction amount of the measured gas of the modules I and II are not equal, and the computer control and analysis module IV selects and analyzes the information of the modules I and II at the same time.

In gas sample introduction monocycle T₀In the method, the electronic nose instrument senses the measured gas at a detection point to obtain an m-dimensional sensing vector x (tau) ∈ R^mIs called as sampleThen, the process is carried out; the gas circulation sample introduction period of the electronic nose instrument to the 5 detection points is T-5T₀And sequentially obtaining 5 samples, sequentially storing the samples in 5 corresponding data files of the computer control and analysis module IV, and sending the sample data to a cloud end and a specified fixed/mobile terminal through the WIFI routing module. If gas sample introduction is performed for a period T₀And (5) 480s, wherein the gas circulation sampling period of the detection points is 2400s, and the detection is equivalent to that of one fermentation tank or one stink pollution point every 40 min.

And odor big data X is formed by online/offline detection and perception of conventional instruments such as an electronic nose instrument, a color/mass spectrum instrument and the like and professionals on a large number of biological fermentation processes or odor pollution points. In the learning stage, the computer controls and analyzes the machine learning model of the module IV to learn the data set X off line so as to determine the structure and the parameters, and learns the near term perception information of the gas-sensitive/gas chromatography on line so as to fine-tune the parameters of the machine learning model. In a decision stage, a machine learning model determines a biological fermentation type and a malodor pollution type on line according to a current sensing vector x (tau) of a gas-sensitive/gas chromatography, and quantitatively predicts the concentration of main components of fermentation liquor or an odor concentration OU value and the concentrations of 8 malodor components specified by the national standard GB 14554.

The gas sensor array I-1 and the annular working cavity I-2 thereof are positioned in a thermostat with the temperature of 55 +/-0.1 ℃. In gas sample introduction monocycle T₀In the gas sensor array module I, the initial recovery T of the gas sensor array is sequentially carried out₀120s, accurate calibration of clean air for 40s, balance for 5s, headspace sampling of measured gas for 60s, transition for 5s and flushing of ambient purified air for 10s, wherein the 6 stages have the gas types and flow rates of ① ambient purified air 6,500ml/min, ② clean air 1,000ml/min, ③ no-flow gas, ④ measured gas 1,000ml/min, ⑤ ambient purified air 1,000ml/min and ⑥ ambient purified air 6,500ml/min in sequence, and the transition mainly refers to the conversion from the measured gas to the ambient purified air.

Gas sample introduction monocycle T₀[ T ] of₀-75s,T₀-15s]The time interval is the tested gas headspace sample injection stage of the gas sensor array module I, and one of the 5 two-position two-way solenoid valves III-k (k is 1,2, …,5) from the first to the fifth) And (4) conducting, wherein the three-position four-way solenoid valve III-12 is in the position of 0, the sixth and seventh two-position two-way solenoid valves III-9 are disconnected with the valve III-14, and the eighth two-position two-way solenoid valve III-15 is conducted. Under the pumping action of the first micro vacuum pump III-7, the gas to be measured at one detection point sequentially flows through a k two-position two-way solenoid valve III-k (k is 1,2, …,5), an eighth two-position two-way solenoid valve III-15, a pressure stabilizing valve III-16, an annular working chamber I-2 and a gas sensor array I-1 inside the annular working chamber I-2, a first throttling valve III-10 and a first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 60 s. The gas sensor array I-1 thus generates a sensitive response to the gas to be measured and is stored in a temporary file in the computer control and analysis module IV.

Gas sample introduction monocycle T₀[ T ] of₀-120s,T₀-80s]The time interval is the clean air calibration stage of the gas sensor array module I, the three-position four-way electromagnetic valve III-12 is in the position of '1', the sixth, seventh and eighth two-position two-way electromagnetic valves III-9, III-14 and III-15 are all disconnected, clean air in the clean air bottle V-2 sequentially flows through the first pressure reducing valve III-17, the second throttling valve III-18, the second purifier III-19, the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1, the first throttling valve III-10 and the first flow meter III-8 in the annular working cavity I-2 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 40 s. During this time, the gas sensor array I-1 is accurately restored to the reference state by the clean air. As the eighth two-position two-way solenoid valve III-15 is disconnected, whether the 5 first to fifth two-position two-way solenoid valves III-1 to III-5 are connected or not does not influence the calibration of the gas sensor array I-1.

The 'environment purified air' refers to air obtained after dust removal, dehumidification and sterile treatment of outdoor air where the electronic nose instrument is located, and is only used for primary recovery of the gas sensor array I-1, flushing of the inner walls of the annular working cavity I-2 and related gas circuit pipelines and carrying away of accumulated heat of the gas sensor array. In gas sample introduction monocycle T₀Is [0, T ]₀-120s]And [ T₀-10s,T₀]In the two time periods, the three-position four-way electromagnetic valve III-12 is in the position of 2', and the sixth position isThe two-position two-way solenoid valve III-9 is conducted, the eighth two-position two-way solenoid valve III-15 is disconnected, the environment purified air sequentially flows through the three-position four-way solenoid valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1, the sixth two-position two-way solenoid valve III-9 and the first flow meter III-8 in the annular working cavity at the flow rate of 6,500ml/min, and is finally discharged to the outside for T₀-110 s. During the period, the gas sensor array I-1 is preliminarily restored to the reference state under the action of the environment purified air; as the eighth two-position two-way solenoid valve III-15 is disconnected, whether the first to fifth 5 two-position two-way solenoid valves III-1 to III-5 are connected or not does not influence the initial recovery of the gas sensor array I-1.

The size of the commercial capillary chromatographic column II-1 is determined by default that the length L× internal diameter phi d × film thickness is 30m × phi 0.53mm × 0.25.25 mu m, and the capillary chromatographic column II-1 is positioned in a constant temperature box with the temperature of 300 +/-0.1 ℃ at the single period T in gas injection₀The capillary gas chromatographic column module II sequentially undergoes the headspace sample injection for 1s and the chromatographic separation for the gas to be detected T₀16s, and 15s of emptying and cleaning purging; h₂It can be used as both carrier gas and fuel gas, and the clean air is used as combustion-supporting gas.

Gas sample introduction monocycle T₀The first 1s is a tested gas headspace sample injection stage of the capillary gas chromatography column module II, one of the first to fifth two-position two-way solenoid valves III-k (k is 1,2, …,5) is turned on, the two-position three-way solenoid valve III-11 is at the position "1", the seventh two-position two-way solenoid valve III-14 is turned on, and the eighth two-position two-way solenoid valve III-15 is turned off. At this time, the gas to be detected at the detection point k flows through one of the first to fifth two-position two-way electromagnetic valves III-k (k is 1,2, …,5), the seventh two-position two-way electromagnetic valve III-14, the two-position three-way electromagnetic valve III-11 and the fourth throttle valve III-24 in sequence under the suction action of the second micro vacuum pump III-13, and is mixed with the carrier gas H at the injection port II-5₂Mixed and therefore flowed into capillary gas chromatography column II-1 for 1 s; the default sample injection flow of the gas to be detected is 6ml/min, the default sample injection duration is 1s, and the default cumulative sample injection amount is 0.1 ml.

Gas sample introduction monocycle T₀Of [1s, T₀-10s]The time interval is the measured gas separation stage of the capillary gas chromatographic column module II, and the two-position tee jointThe solenoid valve III-11 is in the position "2", the seventh two-position two-way solenoid valve III-14 is open, and the gas to be measured from the detection point k is therefore open for a time T₀-11 s. Carrier gas H with certain pressure and flow rate of gas to be detected injected into sample inlet II-5 of gas chromatographic column module II₂Under the pushing action of the pressure sensor, separation is generated in a capillary gas chromatographic column II-1, a detector II-2 generates sensing accordingly, and after the sensing is amplified by an amplifier II-3, a recorder II-4 is used for recording [0, T ]₀-10s]Time interval, i.e. length T of chromatographic column II-1₀The perceived response of-10 s is recorded and stored in a temporary file of the computer control and analysis module IV.

Gas sample introduction monocycle T₀Last 10s of (i.e. [ T ]₀-10s,T₀]The time interval is the emptying, namely the cleaning and purging stage of the capillary gas chromatographic column II-1, and in the 5 two-position two-way electromagnetic valves III-1-III-5 from the first to the fifth, the originally conducted one, namely III-k, is disconnected, and the originally closed one, namely III- (-k), of the other 4, namely III- (-k) is conducted; the two-position three-way electromagnetic valve III-11 is in the position of 2, the seventh two-position two-way electromagnetic valve III-14 is conducted, and the eighth two-position two-way electromagnetic valve III-15 is disconnected. At this time, the two-position two-way solenoid valve III- (-k) is turned on (k ═ 1,2, …,5), and the air flows through the two-position two-way solenoid valve III- (-k), the seventh two-position two-way solenoid valve III-14, and the two-position three-way solenoid valve III-11 in this order at a flow rate of 330ml/min under the suction action of the second micro vacuum pump III-13, and is directly discharged to the outside. The stage has the function of eliminating the residual smell from the kth detection point of the related pipeline in the current gas injection single period, gradually replacing the residual smell by the detected gas from the kth detection point, and preparing for detecting another biological fermentation process or odor pollution monitoring point in the next gas injection single period for 10 s.

Gas sample introduction monocycle T₀[ T ] of₀-10s,T₀]The time interval is the information selection and analysis time period of the gas sensor array I module and the capillary chromatographic column module II at the same time, and the computer control and analysis module IV is controlled from [ T [ ]₀-75s,T₀-15s]Selection of a steady state peak value v in a time-sliced gas sensor array I-1 voltage response curve_gsi(τ) and the like; from [0, T₀-10s]Selecting the first 10 maximum chromatographic peaks v on the chromatogram of the time segment_gci(τ) and the like. The method is the basis for establishing odor big data and analyzing the biological fermentation process or the odor pollution area by an electronic nose instrument. And the computer control and analysis module IV carries out odor type identification and intensity and main concentration index value quantitative prediction according to the perception vector x (tau).

In gas sample introduction monocycle T₀In this case, when there is only one detection point, the gas circulation detection and analysis period is T ═ T₀(ii) a If k (═ 2,3,4,5) detection points are detected simultaneously, the cycle detection and analysis period is T ═ k × T₀. In the long-term circulation monitoring process, if one detection point exits, the circulation detection and analysis period is changed into T ═ k-1 × (T)₀(ii) a Similarly, in the long-term cycle monitoring process, if a new detection point is added halfway, the cycle detection and analysis period becomes T ═ k +1 × T₀(ii) a And from the exit/entrance moment of one detection point, the corresponding data file recording period correspondingly changes.

The long-term circulating online detection and online analysis prediction of the electronic nose instrument on a plurality of biological fermentation processes/odor pollution points comprises the following steps:

(1) starting up: preheating the instrument for 30 min;

modification of screen menu' gas sample introduction monocycle T₀"set, Default value T₀8 min; the gas circulation sampling period of the 5 detection points is T-5T₀。

The three-position four-way electromagnetic valve III-12 is in the position of 2, the sixth two-position two-way electromagnetic valve III-9 is conducted, and the eighth two-position two-way electromagnetic valve III-15 is disconnected. Under the suction action of the first micro vacuum pump III-7, environment purified air sequentially flows through the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1 thereof, the sixth two-position two-way electromagnetic valve III-9 and the first flow meter III-8 at the flow rate of 6,500ml/min, and is finally discharged to the outside. The internal temperature of the annular working cavity I-1 of the gas sensor array reaches 55 +/-0.1 ℃ which is constant.

The two-position three-way electromagnetic valve III-11 is at the position of 2', and the seventh two-position two-way valve is electrifiedThe magnetic valve III-14 is disconnected and the carrier gas H₂Under the pushing action of the pressure sensor, the capillary gas chromatographic column II-1 is gradually restored to a reference state, and the internal temperature of the chromatographic column box reaches constant 250 +/-0.1 ℃.

(2) Beginning a gas circulation sample introduction period: clicking a 'detection point k on' option of a screen menu of a display IV-5, wherein k is 1,2, …,5, and continuously detecting by the electronic nose instrument for a long time until an operator clicks a 'detection point k off' option; the electronic nose instrument carries out cyclic detection on the 5 detection points in sequence, and the computer control and analysis module IV automatically generates 5 text files so as to store the sensing response data of the gas sensor array I-1 and the capillary gas chromatographic column module II to the 5 detection point gases.

(3) Detecting the start of a gas sample introduction single period at a point k; by T₀As an example, 8 min:

(3.1) gas sensor array module I:

(3.1a) preliminary recovery: in gas sample introduction monocycle T₀In 0-360s, the three-position four-way electromagnetic valve III-12 is in the position of 2, the sixth two-position two-way electromagnetic valve III-9 is switched on, and the eighth two-position two-way electromagnetic valve III-15 is switched off; under the suction action of a first micro vacuum pump III-7, environment purified air sequentially flows through a three-position four-way electromagnetic valve III-12, a pressure stabilizing valve III-16, an annular working cavity I-2 and a gas sensor array I-1 thereof, a sixth two-position two-way electromagnetic valve III-9 and a first flow meter III-8 at the flow rate of 6,500ml/min, and is finally discharged to the outside; the gas sensor array I-1 is preliminarily restored to the reference state.

(3.1b) precise calibration: in gas sample introduction monocycle T₀400s in 360 th mode, the three-position four-way electromagnetic valve III-12 is in the position of 1', the sixth, seventh and eighth two-position two-way electromagnetic valves III-9, III-14 and III-15 are all disconnected, clean air sequentially flows through the first pressure reducing valve III-17, the second throttle valve III-18, the second purifier III-19, the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working chamber I-2 and the gas sensor array I-1 in the annular working chamber I-2, the first throttle valve III-10 and the first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 40 s; the gas sensor array I-1 is thus restored accurately to the reference state.

(3.1c) balance: in gas sample introduction monocycle T₀400 th-405 th s, the three-position four-way solenoid valve III-12 is in the position of 0', the sixth and eighth two-position two-way solenoid valves III-9 and III-15 are disconnected, and no gas flows in the annular working cavity I-2 of the gas sensor array for 5 s.

(3.1d) headspace sampling: in gas sample introduction monocycle T₀405-; under the pumping action of a first micro vacuum pump III-7, the gas to be detected at one detection point sequentially flows through a two-position two-way electromagnetic valve III-k (k is 1,2, …,5), an eighth two-position two-way electromagnetic valve III-15, a pressure stabilizing valve III-16, an annular working chamber I-2 and a gas sensor array I-1 thereof, a first throttling valve III-10 and a first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 60 s; the sensitive response generated by the gas sensor array I-1 is stored in a temporary file corresponding to the computer control and analysis module IV.

(3.1e) transition: in gas sample introduction monocycle T₀465 th and 470s, the three-position four-way solenoid valve III-12 is in the position of '2', the eighth two-position two-way solenoid valve III-15 is disconnected, and the sixth and seventh two-position two-way solenoid valves III-9 and III-14 are kept disconnected; under the suction action of the first micro vacuum pump III-7, environment purified air sequentially flows through the three-position four-way electromagnetic valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1 thereof, the sixth two-position two-way electromagnetic valve III-9 and the first flow meter III-8 at the flow rate of 1,000ml/min, and is finally discharged to the outside.

(3.1f) cleaning: in gas sample introduction monocycle T₀470-480s, compared with the "transition" stage, the positions of the other valves are the same except that the sixth two-position two-way solenoid valve III-9 is changed from "off" to "on"; the ambient purge air flow rate was thus changed from "1,000 ml/min" to "6,500 ml/min". The valve position and the working state of the stage are completely the same and are connected with the valve position and the working state of the next single-cycle initial recovery stage to be started.

(3.2) capillary gas chromatography column II module:

(3.2a) headspace sampling: in gas sample introduction monocycle T₀0-1s, one of the 5 two-position two-way electromagnetic valves III-k (k is 1,2, …,5) is turned on, the two-position three-way electromagnetic valve III-11 is at the position "1", the seventh two-position two-way electromagnetic valve III-14 is turned on, and the eighth two-position two-way electromagnetic valve III-15 is turned off; under the suction action of the second micro vacuum pump III-13, the gas to be detected at the detection point k sequentially flows through one of the first to fifth two-position two-way electromagnetic valves III-k (k is 1,2, …,5), the seventh two-position two-way electromagnetic valve III-14, the two-position three-way electromagnetic valve III-11 and the fourth throttle valve III-24, and is mixed with carrier gas H at the injection port II-5₂Mix and flow into capillary gas chromatography column II-1 for 1 s.

(3.2b) chromatographic separation: in gas sample introduction monocycle T₀1-470s, the two-position three-way electromagnetic valve III-11 is in the position of 2, and the seventh two-position two-way electromagnetic valve III-14 is disconnected; carrier gas H of measured gas under certain pressure and flow₂Under the driving action of the sensor, the sensor II-2 generates sensing response in the capillary gas chromatographic column II-1, and after the sensing response is amplified by the amplifier II-3, the recorder II-4 will generate 0,470s]The perceptual response of interval duration 470s is recorded to form a semi-separated chromatogram peak map and stored in a temporary file of computer control and analysis module IV.

(3.3) information selection and analysis: in gas sample introduction monocycle T₀470-480s, the computer control and analysis module IV from 405s,465s]Selecting steady state peak value v in each gas sensor voltage response curve of time period_gsi(τ) and the like; from [0,470s]Selecting 10 maximum chromatographic peaks v on the chromatogram of the time segment_gci(τ), etc. In gas sample introduction monocycle T₀In the system, the computer control and analysis module IV obtains 1 m-dimensional sensing vector x (tau) ∈ R from the sensing information of the gas sensor array I module and the capillary chromatographic column module II^m(ii) a Then, the machine learning model carries out odor type identification and intensity and main component quantitative prediction according to the perception vector x (tau), the monitor displays the monitoring and prediction results, and transmits the results to the center through the InternetA control room and a plurality of fixed/mobile terminals.

(3.4) end of detection point k and start of the next detection point:

one of the first to fifth 5 two-position two-way solenoid valves III-k (k is 1,2, …,5) is turned off from the original on state, and one of the first to fifth two-position two-way solenoid valves corresponding to the next detection point is turned on.

(4) And (5) repeating the steps (3.1) to (3.4), and realizing the circulation online detection, identification and multi-item concentration index value quantitative prediction of the detected gas at 1-5 detection points by the electronic nose instrument.

Drawings

FIG. 1 is a schematic diagram of the technical route of the gas-sensitive/gas-chromatographic perception information fusion, the development of the electronic nose instrument and the on-line odor detection and analysis, which are the gas-sensitive/gas-chromatographic fusion electronic nose instrument on-line detection and analysis method of the invention.

FIG. 2 is a schematic view of the online detection and analysis method of the electronic nose instrument integrated with gas-sensitive/gas chromatography, which is the working principle of the electronic nose instrument.

FIG. 3 is a schematic diagram of the gas sensor array module and its gas circuit working principle, which is an online detection and analysis method of the gas-sensitive/gas chromatography integrated electronic nose instrument of the present invention.

FIG. 4 is a schematic diagram of the on-line detection and analysis method of the invention, capillary gas chromatographic column module and its gas circuit working principle.

FIG. 5 is a schematic diagram of a gas sensor array module and a capillary gas chromatography column module, which are the gas-sensitive/gas chromatography-fused online detection and analysis method of an electronic nose instrument.

FIG. 6 shows the on-line detection and analysis method of the present invention, gas-sensitive/gas chromatography integrated electronic nose instrument, gas sample injection single period T₀And in 480s, the gas sample introduction time, the gas flow and the response change condition of the gas-sensitive sensor of the capillary chromatographic column and the gas-sensitive sensor array module are schematically shown.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

FIG. 1 is a schematic diagram of the technical route of the gas sensor array and capillary gas chromatographic column sensing information fusion, electronic nose instrument development and odor on-line detection and analysis.

The technical route shown in fig. 1 includes: (1) and evaluating and selecting the performance of the gas-sensitive and chromatographic sensing element. The characteristic difference between the gas sensor and the capillary gas chromatographic column is deeply analyzed, and the advantages of the gas sensor and the capillary gas chromatographic column are made good for. (2) And the components such as the gas sensor array are modularized. The gas sensor array, the capillary gas chromatographic column, the automatic gas sample introduction, the computer control and analysis and other important components realize the structure modularization. (3) And the gas-sensitive/chromatographic online perception model is fused with information. The invention discloses a gas sensor response curve multi-information selection method meeting the principle of triangular stability and a semi-separation chromatogram multi-information selection method simulating a marathon competition scene, and realizes on-line sensing and information fusion of a gas sensor array and a capillary chromatographic column. (4) And establishing smell big data. The odor big data X is formed on the basis of conventional instrument off-line detection data such as gas-sensitive/chromatographic multi-source on-line perception data of an electronic nose instrument for a large number of biological fermentation processes or odor pollution points, professional laboratory odor identification data, color/mass spectrum and spectrophotometry. (5) And off-line learning and on-line fine tuning of the machine learning model. The machine learning model learns the odor big data X in an off-line manner so as to optimize and determine the structure and parameters of the model; in a decision stage, a machine learning model online learns the recent response of the gas-sensitive/chromatographic system to fine-tune parameters, online determines the biological fermentation process or the odor pollution type according to the current sensing vector x (tau) of the gas-sensitive/gas-phase, quantitatively predicts the concentration of the main components of fermentation liquor in the biological fermentation process or the concentration of 8 components of the odor pollutant and the concentration of the odor OU specified by the national standard GB14554, and realizes the long-term circulation online detection and online analysis of complex odors of a plurality of biological fermentation processes and a plurality of odor pollution points.

Fig. 2 is a schematic diagram of the working principle of the gas-sensitive/gas-chromatographic fused electronic nose instrument of the invention. The electronic nose instrument mainly comprises: a gas sensor array module I, a capillary gas chromatographic column module II, a gas automatic sampling system module III, a computer control and analysis module IV, a hydrogen cylinder V and a clean air cylinder VI. The hydrogen is also used as carrier gas and fuel gas of a capillary gas chromatographic column module II hydrogen flame ionization detector FID; the clean air is used as combustion-supporting gas of the capillary chromatographic column module II on one hand and as calibration gas (not burning) of the gas sensor array module I on the other hand.

Fig. 3 and 4 are schematic diagrams of an array module I of a gas sensor of an electronic nose instrument, a capillary gas chromatographic column module II and a gas circuit working principle thereof, respectively.

The gas sensor array module I mainly comprises the following components: the gas sensor array I-1, the gas sensor array annular working cavity I-2, the resistance heating element I-3, the fan I-4, the heat insulation layer I-5 and the partition plate I-6 are positioned in the right middle of the electronic nose instrument. The capillary gas chromatographic column module II mainly comprises the following components: the capillary gas chromatographic column II-1, the detector II-2, the amplifier II-3, the recorder II-4, the sample inlet II-5, the resistance heating wire II-6, the fan II-7 and the heat insulation layer II-8 are positioned at the upper right part of the electronic nose instrument. The gas sensor array module I and the capillary gas chromatographic column module II are used for converting chemical and physical information of the smell into electric signals on line.

The gas automatic sampling system module III and the gas sensor array module I are related to each other, and the composition units comprise: the device comprises first to fifth two-position two-way electromagnetic valves III-1 to III-5, a first purifier III-6, a first micro vacuum pump III-7, a first flow meter III-8, a sixth two-position two-way electromagnetic valve III-9, a first throttle valve III-10, a three-position four-way electromagnetic valve III-12, a seventh two-position two-way electromagnetic valve III-14, an eighth two-position two-way electromagnetic valve III-15, a pressure stabilizing valve III-16, a first pressure reducing valve III-17, a second throttle valve III-18 and a second purifier III-19.

The gas automatic sample introduction system module III and the capillary gas chromatographic column module II are related to each other in the composition units, including: a two-position three-way electromagnetic valve III-11, a second micro vacuum pump III-13, a second pressure reducing valve III-20, a third purifier III-21, a third throttle valve III-22, a second flowmeter III-23, a fourth throttle valve III-24 and a fifth throttle valve III-25. And the gas automatic sampling system module III is positioned at the right lower part of the electronic nose instrument.

The computer control and analysis module IV mainly comprises the following components: the computer mainboard IV-1, the A/D data acquisition card IV-2, the driving and control circuit board IV-3, the 4-path precise direct current stabilized voltage supply IV-4, the display IV-5 and the WIFI module IV-6 are positioned on the left side of the electronic nose instrument. And the WIFI module IV-6 is used for transmitting the sensing information of the gas sensor array module I and the capillary gas chromatographic column module II to a specified fixed/mobile terminal in real time.

FIG. 5 is a schematic diagram of gas sensor array module I and capillary gas chromatography column module II of an electronic nose instrument. The two modules can be conveniently replaced according to the needs.

FIG. 6 shows the electronic nose apparatus in the gas sample injection period T₀And (3) the gas sampling time, the gas sampling flow and the gas sensor response change condition of the gas sensor array module I and the capillary gas chromatographic column module II are shown in 480 s.

The gas sample introduction period can be in T₀Adjusting the sampling time between 5min and 10min, and only giving a default gas sampling single period T in figure 6₀For example 480 s. The adjustable time period mainly comprises an environment purified air flushing/gas sensor initial recovery stage of the gas sensor array module I and a separation stage of the capillary gas chromatographic column module II. FIG. 6 shows that the gas injection period is T₀In 480s, the sample introduction flow rate of the gas sensor array module I and the capillary gas chromatographic column module II to be detected is not equal to the accumulated sample introduction amount, the sample introduction time is asynchronous, and the information selection and the analysis area are simultaneously carried out in the last 10s stage.

FIG. 6(a) shows the gas sample injection single cycle condition of capillary chromatographic column module II, comprising ① tested gas headspace sample injection, ② tested gas chromatographic separation and ③ chromatographic column emptying 3 stages, ① tested gas headspace sample injection stage is in sample injection single cycle T₀In the initial stage of (1), the sample introduction time range is 0.5-1.5 s, and the default time is 1 s; the sample introduction flow range is 1.5-15 ml/min, and the default is 6 ml/min; the range of the cumulative sample injection amount is 0.0125-0.375 ml, and the default is 0.1 ml.

Referring to FIG. 6 in conjunction with FIG. 4, Table 1 shows the single cycle T in gas injection₀Capillary gas chromatographic column mould in 480sAt ①, the two-position three-way electromagnetic valve III-11 is at position '1', the seventh two-position two-way electromagnetic valve III-14 is conducted, one of the first to fifth two-position two-way electromagnetic valves III-1 to III-5 is conducted, the eighth two-position two-way electromagnetic valve III-15 is disconnected, and if the first two-position two-way electromagnetic valve III-1 is conducted, at this time, the tested gas in a biological fermentation process (fermentation tank) or an odor pollution point, such as a first detection point, flows through the first two-position two-way electromagnetic valve III-1, the seventh two-position two-way electromagnetic valve III-14, the two-position three-way electromagnetic valve III-11 and the fourth throttle valve III-24 in sequence under the suction effect of the second micro vacuum pump III-13, and the carrier gas H at the sample inlet II-5₂Mixed and thus flowed into capillary gas chromatography column II-1.

At the stage ① of sample injection of the gas to be detected, if the default sample injection flow rate is 6ml/min and the default sample injection duration is 1s, the sample injection amount of the gas to be detected is 0.1ml, which meets the requirement of the best sample injection amount of the capillary gas chromatographic column.

At T₀When the chromatographic separation phase ② lasts 369s, 480s, the two-position, three-way solenoid valve III-11 is in position "2", the seventh two-position, two-way solenoid valve III-14 is open, i.e. the gas to be measured is open₂Under the pushing action of the pressure sensor, the detected gas is separated in the capillary gas chromatographic column II-1.

In gas sample introduction monocycle T₀The last 10s column blowdown phase ③, i.e., the purge, purge phase, with the two-position, three-way solenoid valve III-11 in position

TABLE 1 gas sample introduction monocycle T₀300-

Set to "2", the seventh two-position two-way solenoid valve III-14 is conducted, first toOne of the fifth 5 two-position two-way solenoid valves III-1 to III-5 is conducted (but closed originally), and the eighth two-position two-way solenoid valve III-15 is disconnected. Assuming that the first two-position two-way solenoid valve III-1 is conducted, the air flows through the first two-position two-way solenoid valve III-1, the seventh two-position two-way solenoid valve III-14 and the two-position three-way solenoid valve III-11 in sequence under the suction action of the second micro vacuum pump III-13 and is then discharged to the outside. The effect of this stage is to clear away the residue of the relevant pipeline in this gas sampling single cycle and prepare for the next gas sampling single cycle. It must be noted that the position of the three-position, four-way solenoid valve III-12 is determined by Table 2 given later.

Referring to FIG. 6 in conjunction with FIG. 3, Table 2 shows the single cycle T in gas injection₀And working parameters of the gas sensor array module I and the on/off state of a relevant electromagnetic valve.

Following single cycle T with gas injection₀Several main operating states of the gas sensor array module I are explained in detail, 480s being an example.

At the stage ④ of tested gas headspace sample injection, i.e. gas sample injection single period T₀In the time period of 405 plus 465s, one of the 5 first to fifth two-position two-way solenoid valves III-1 to III-5 is conducted, the three-position four-way solenoid valve III-12 is at the position of '0', the sixth and seventh two-position two-way solenoid valves III-9 and III-14 are disconnected, and the eighth two-position two-way solenoid valve III-15 is conducted. Under the pumping action of a first micro vacuum pump III-7, the gas to be detected in one of 5 biological fermentation processes (fermentation tanks) or foul smell pollution points (such as a first detection point) sequentially flows through one of the 5 two-position two-way electromagnetic valves III-1 to III-5, the eighth two-position two-way electromagnetic valve III-15, a pressure stabilizing valve III-16, an annular working cavity I-2 and a gas sensor array I-1, a first throttling valve III-10 and a first flow meter III-8 in the annular working cavity I-2 at the flow rate of 1,000ml/min, and is finally discharged to the outside for 60 s. During this time, the gas sensor array I-1 generates a sensitive response to the gas under test.

In the clean air calibration stage ②, i.e. gas injection single cycle T₀In the period of 360-400s, the three-position four-way solenoid valve III-12 is in the position of '1', and the sixth, seventh and eighth two-position two-way solenoid valvesIII-9, III-14 and III-15 are disconnected, the clean air in the clean air bottle VI flows through a first reducing valve III-17, a second throttling valve III-18, a second purifier III-19, a three-position four-way electromagnetic valve III-12, a pressure stabilizing valve III-16, an annular working chamber I-2 and a gas sensor array I-1 thereof, a first throttling valve III-10 and a first flow meter III-8 in sequence at the flow rate of 1,000ml/min, and is finally discharged to the outside for 40 s. During this time, the gas sensor array I-1 is accurately restored to the reference state by the clean air. Because the eighth two-position two-way electromagnetic valve III-15 is disconnected, whether the first to fifth five two-position two-way electromagnetic valves III-1 to III-5 are connected or disconnected does not influence the calibration of the gas sensor array I-1.

In the initial recovery stage ① and the environmental clean air flushing stage ⑥ of the gas sensor, i.e. gas injection single period T₀In the two time periods of 0-360s and 470-480, the three-position four-way solenoid valve III-12 is in the position of '2', the sixth two-position two-way solenoid valve III-9 is conducted, the eighth two-position two-way solenoid valve III-15 is disconnected, the environment purified air sequentially flows through the three-position four-way solenoid valve III-12, the pressure stabilizing valve III-16, the annular working cavity I-2 and the gas sensor array I-1 in the annular working cavity I-2, the sixth two-position two-way solenoid valve III-9 and the first flow meter III-8 at the flow rate of 6,500ml/min, and is finally discharged to the outside for 370 s. Under the action of environment purified air, the gas sensor array I-1 is preliminarily restored to a reference state. As the eighth two-position two-way solenoid valve III-15 is disconnected, whether the first to fifth two-way solenoid valves III-1 to III-5 and the sixth and seventh two-position two-way solenoid valves III-9 and III-14 are connected or disconnected does not affect the initial recovery of the gas sensor array I-1.

It should be noted that "ambient purified air" refers to air obtained by subjecting outdoor air where the electronic nose instrument is located to dust removal, dehumidification and sterilization, and is only used for preliminary recovery of the gas sensor array I-1, flushing of the annular working chamber I-2 of the gas sensor array and the inner wall of the related gas path pipeline, and carrying away of accumulated heat of the gas sensor array.

Referring to FIG. 6, in a gas injection single period T₀In the last 10s time period, the gas sensor array module I and the capillary gas chromatographic column module II enter the information simultaneouslyAnd (4) selecting and analyzing the region. Computer control and analysis module IV from [ T ]₀-75s,T₀-15s]Selecting a steady state peak value v in each gas sensor voltage response curve of a time period_gsi(τ), corresponding time to peak t_gsi(τ), area under curve Ags_i(τ) the 3 pieces of perceptual information; from [0, T₀-10s]Selecting the first 10 maximum chromatographic peaks v on the chromatogram of the time segment_gci(τ) and corresponding 10 retention times t_gci(τ), area A under chromatogram Curve_gc(τ), 21 chromatographic perceptual components in total. The method is the basis for analyzing and predicting a biological fermentation process or a foul odor pollution area by an electronic nose instrument, and is the basis for establishing odor big data X; and the machine learning model of the computer control and analysis module IV identifies the odor type and quantitatively predicts the intensity and the main concentration index value according to the perception vector x (tau).