阅读说明：本技术 一种网络化分布的co2在线连续检测系统及检测方法 (CO distributed in network2Online continuous detection system and detection method ) 是由 何镧 刘佳琪 王成宇 于 2019-12-17 设计创作，主要内容包括：本发明涉及一种网络化分布的CO<Sub>2</Sub>在线连续检测系统及检测方法。包括多个扩散式CO<Sub>2</Sub>检测节点,置于地表或地下浅层,用于检测土壤中CO<Sub>2</Sub>气体浓度,通过信号线将检测信号传输给节点控制器；节点控制器,与扩散式CO<Sub>2</Sub>检测节点一一对应,为扩散式CO<Sub>2</Sub>检测节点提供电源,并将扩散式CO<Sub>2</Sub>检测节点送来的检测信号通过无线网络传输给远程的监测终端；监测终端,与节点控制器进行无线通信,接收节点控制器传输的数据,进行显示和储存,并对接收到的数据进行处理和分析,以甄别扩散式CO<Sub>2</Sub>检测节点检测到的CO<Sub>2</Sub>气体浓度是否有异常变化。本发明能大面积实时连续监测CO<Sub>2</Sub>的浓度变化,且不影响测量气体原始状态,提高检测的准确性,具备空间化CO<Sub>2</Sub>浓度分析功能,分析结果更加可靠。(The invention relates to a network distributed CO 2 An on-line continuous detection system and a detection method. Comprising a plurality of diffusing CO 2 Detection node arranged on surface or underground shallow layer for detecting CO in soil 2 The gas concentration transmits a detection signal to the node controller through a signal wire; node controller, and diffusion CO 2 The detection nodes are in one-to-one correspondence and are diffusion type CO 2 The detection node provides power and diffuses CO 2 The detection signal sent by the detection node is transmitted to a remote monitoring terminal through a wireless network; the monitoring terminal is in wireless communication with the node controller, receives the data transmitted by the node controller, displays and stores the data, and processes and analyzes the received data to discriminate the diffusion CO 2 Detecting CO detected by a node 2 Whether there is an abnormal change in the gas concentration. The invention can continuously monitor CO in real time in large area 2 The concentration of the gas is changed, the original state of the measured gas is not influenced, the detection accuracy is improved, and the method has the advantages of spatialization of CO 2 The concentration analysis function and the analysis result are more reliable.)

1. CO distributed in network₂An on-line continuous detection system, comprising:

multiple diffusion type CO₂Detection node arranged on surface or underground shallow layer for detecting CO in soil₂The gas concentration transmits a detection signal to the node controller through a signal wire;

node controller, and diffusion CO₂The detection nodes are in one-to-one correspondence and are diffusion type CO₂The detection node provides power and diffuses CO₂The detection signal sent by the detection node is transmitted to a remote monitoring terminal through a wireless network;

the monitoring terminal is in wireless communication with the node controller, receives the data transmitted by the node controller, displays and stores the data, and processes and analyzes the received data to discriminate the diffusion CO₂Detecting CO detected by a node₂Whether there is an abnormal change in the gas concentration.

2. A network distributed CO according to claim 1₂The on-line continuous detection system is characterized in that the diffusion type CO is₂The detection node is a detection rod, the head of the detection rod is provided with a double-channel structure sensor, and the rear of the double-channel structure sensor is provided withAnd the detection circuit is connected with the dual-channel structure sensor through a probe and is connected with the node controller through a plurality of strands of shielding signal wires.

3. A networked CO according to claim 2₂The on-line continuous detection system is characterized in that the dual-channel structure sensor comprises a piezoelectric layer, two interdigital electrodes which are arranged side by side are arranged on the piezoelectric layer, a gas-sensitive film is coated on one interdigital electrode to form a gas-sensitive element, and the gas-sensitive film is MWCNTs/SnO₂The two interdigital electrodes are respectively positioned in two detection channels of the two-channel structure sensor.

4. A networked CO according to claim 3₂The on-line continuous detection system is characterized in that the front end of the detection rod is covered with a layer of hydrophobic breathable film, namely, the air inlet of the dual-channel structure sensor is covered with a layer of hydrophobic breathable film, the hydrophobic breathable film is a microporous PTFE hydrophobic filter film, and a distance is reserved between the interdigital electrode and the hydrophobic breathable film.

5. A networked CO according to claim 3 or 4₂The on-line continuous detection system is characterized in that the piezoelectric layer is made of diamond-like BN (boron nitride), and the interdigital electrode comprises SnO (SnO)₂The thin film layer and the Au thin film layer are formed by double-layer plating.

6. A networked CO according to claim 1 or 2₂The on-line continuous detection system is characterized in that the node controller comprises a power module and a GPRS communication module, the power module comprises a solar cell panel, a storage battery and a power voltage stabilizing chip which are sequentially connected, the output end of the power voltage stabilizing chip is connected with the diffusion type CO₂The detection nodes are connected, and the GPRS communication module is used for diffusing CO₂And the detection signal sent by the detection node is transmitted to a remote monitoring terminal through a GPRS wireless network.

7. A networked CO as claimed in claim 1₂The detection method of the on-line continuous detection system is characterized in that the detection method is based on CO₂To the diffused CO₂The detection nodes are distributed, and the node controller is fixed on the ground surface and is a diffusion type CO₂The detection node provides power supply power and CO in the soil₂Free escape of gas to diffusion CO₂In a two-channel structure sensor for detecting nodes, CO₂Gas contacts a gas sensitive element in the dual-channel structure sensor, a gas sensitive film on the gas sensitive element is physically changed to cause phase change of an interdigital electrode, a changed signal is transmitted to a detection circuit through a probe, the detection circuit transmits a detection signal to a node controller after processing, and the node controller transmits detected CO to a node controller through a wireless network₂Transmitting the gas concentration data to the monitoring terminal, and the monitoring terminal transmits all the diffused CO₂Detecting CO measured by a node₂The gas concentration is stored and analyzed, and the monitoring terminal is used for storing and analyzing the same diffused CO₂The concentrations of the detection nodes measured at different times form a group, and the concentration is measured for single diffusion type CO₂And (3) carrying out normal distribution test on the concentration measured by the detection node within a period of time, carrying out sliding variance analysis by taking every 10 concentration data as a data section, finding out the data section with obvious difference by using F statistic so as to find out a period of time with the maximum concentration change in a group, and if the concentration variance in the period of time is greater than a set threshold value, displaying an analysis result by the monitoring terminal and sending alarm information.

Technical Field

The invention relates to the field of gas concentration analysis and detection, in particular to CO distributed in a network manner₂An on-line continuous detection system and a detection method.

Background

Carbon dioxide is abundant in nature and is one of the important constituents of the atmosphere. With the rapid development of industrialization process, CO in the atmosphere₂The concentration is increasing, which brings about many negative effects on global climate, ecological environment and human health. The method is divided into atmospheric monitoring, surface monitoring and stratum monitoring according to different gas monitoring positions. The atmospheric monitoring is developed more mature mainly aiming at the fields of environmental pollution, industrial safety and the like, and the detection method comprises a gas chromatography method, an electrochemical method, a contact combustion method and an infrared spectrum absorption method. The gas chromatography and the infrared spectrum absorption method are detection methods which are widely applied, but the gas chromatography is limited by the defect of low measurement efficiency and cannot realize continuous measurement, the infrared spectrum absorption method utilizes gas to enter a sensor for detection, has the advantages of high sensitivity and continuous and rapid measurement, but has the defect that the original state of the measured gas can be damaged to a certain extent by forced air exhaust in the detection process, and meanwhile, the setting of an air pump, a temperature control device and the like greatly increases the system power consumption and increases the difficulty for field long-time measurement.

With the application of CCS technology and the progress of deep earth exploration, CO₂The surface monitoring and the stratum monitoring become a monitoring technology hotspot gradually. Monitoring CO in a region₂The migration condition of the sensor not only needs an accurate concentration detection technology, but also needs a networked and automatic monitoring system, and needs to meet the requirements of no interference and low power consumption, and certain difficulty exists.

Disclosure of Invention

In order to solve the technical problem, the invention provides a CO distributed in a network manner₂The online continuous detection system and the detection method can continuously monitor the surface and the underground shallow layer CO in a large area in real time₂The concentration of (a) is varied,the method does not affect the original state of the measured gas, improves the accuracy and reliability of detection, realizes networked and automatic detection, has less interference and low power consumption, and has spatialization CO₂The concentration analysis function, the analysis result is more reliable and visual.

The technical problem of the invention is mainly solved by the following technical scheme: the invention relates to a network distributed CO₂An on-line continuous detection system comprising:

multiple diffusion type CO₂Detection node arranged on surface or underground shallow layer for detecting CO in soil₂The gas concentration transmits a detection signal to the node controller through a signal wire;

node controller, and diffusion CO₂The detection nodes are in one-to-one correspondence and are diffusion type CO₂The detection node provides power and diffuses CO₂The detection signal sent by the detection node is transmitted to a remote monitoring terminal through a wireless network;

the monitoring terminal is in wireless communication with the node controller, receives the data transmitted by the node controller, displays and stores the data, and processes and analyzes the received data to discriminate the diffusion CO₂Detecting CO detected by a node₂Whether there is an abnormal change in the gas concentration.

The technical scheme forms a networked monitoring system with a plurality of monitoring points, and can continuously monitor the surface and the underground shallow layer CO in a large area in real time₂The concentration change realizes the networking and automatic detection, and has the spatialization CO₂The concentration analysis function, the analysis result is more reliable and visual.

Preferably, the diffusive CO₂The detection node is a detection rod, a double-channel structure sensor is arranged at the head of the detection rod, a detection circuit is arranged behind the double-channel structure sensor and is connected with the double-channel structure sensor through a probe, and the detection circuit is connected with the node controller through a plurality of strands of shielding signal wires. The double-channel structure sensor is provided with two detection channels which are respectively used for arranging a gas sensitive element and a reference element. Gas sensor for adsorbing CO₂Gas, reference elementThe temperature and humidity sensor is used for inhibiting the drift of the temperature and humidity to the detection signal, thereby improving the accuracy and reliability of detection. The sensing signal of the sensor with the double-channel structure is transmitted to a detection circuit, filtered, mixed and difference-frequency analyzed by the detection circuit, and then processed by a digital signal processing circuit to output CO₂And the concentration is transmitted to the node controller through a signal wire. The technical proposal does not need an air pump and a temperature control device, and CO in the soil₂The gas automatically escapes to cause the sensor with a double-channel structure at the head of the detection rod, so that the original state of the measured gas is not influenced, the interference is less, and the power consumption is low.

Preferably, the dual-channel structure sensor comprises a piezoelectric layer, two interdigital electrodes are arranged on the piezoelectric layer side by side, one interdigital electrode is coated with a gas-sensitive film to form a gas-sensitive element, and the gas-sensitive film is MWCNTs/SnO₂The two interdigital electrodes are respectively positioned in two detection channels of the two-channel structure sensor. The interdigital electrode coated with the gas-sensitive film is a gas-sensitive element, and the other interdigital electrode is a reference element. MWCNTs to CO in gas-sensitive films₂Gas has strong adsorbability and is a good conductor, SnO₂Is an oxide which is common in a gas sensitive film, has obvious physical response to gas, has gas-sensitive conductivity better than that of a metal oxide but has poor linearity, and thus, the oxide can be used for preparing a gas-sensitive material by SnO₂/polymer composite enhanced gas-sensitive film for CO₂The gas is linearly responded, and the MWCNTs are used for functionalizing the composite film, so that the adsorbability and the conductivity of the gas-sensitive film are increased, and the response working frequency of a gas-sensitive element is improved. Mixing the MWCNTs polymer solution with SnO2 powder, fully mixing SnO2 with the MWCNTs polymer solution through ultrasonic stirring, controlling the air injection amount to spray the MWCNTs/SnO 2/polymer on an interdigital electrode, and finally performing vacuum drying at 80 ℃ to remove the solvent.

Preferably, the front end of the detection rod is covered with a layer of hydrophobic breathable film, namely, the air inlet of the dual-channel structure sensor is covered with a layer of hydrophobic breathable film, the hydrophobic breathable film is a microporous PTFE hydrophobic filter film, and a distance is reserved between the interdigital electrode and the hydrophobic breathable film. The hydrophobic breathable film is used for blocking water and dust in soil and preventing the gas sensitive element from being damaged due to direct contact with the water or the dust.

Preferably, the piezoelectric layer is made of diamond-like BN, and the interdigital electrodes comprise SnO₂The thin film layer and the Au thin film layer are formed by double-layer plating. Diamond-like BN not only has good piezoelectric properties, but also absorbs little water vapor and causes no noise in the signal response process.

Preferably, the node controller comprises a power module and a GPRS communication module, the power module comprises a solar cell panel, a storage battery and a power voltage stabilizing chip which are sequentially connected, and the output end of the power voltage stabilizing chip and the diffusion type CO are connected₂The detection nodes are connected, and the GPRS communication module is used for diffusing CO₂And the detection signal sent by the detection node is transmitted to a remote monitoring terminal through a GPRS wireless network. The solar cell panel is adopted, so that the solar cell panel is suitable for being installed and used in the field and is convenient for continuous detection.

The invention relates to a network distributed CO₂The detection method of the on-line continuous detection system comprises the following steps: according to CO₂To the diffused CO₂The detection nodes are distributed, and the node controller is fixed on the ground surface and is a diffusion type CO₂The detection node provides power supply power and CO in the soil₂Free escape of gas to diffusion CO₂In a two-channel structure sensor for detecting nodes, CO₂Gas contacts a gas sensitive element in the dual-channel structure sensor, a gas sensitive film on the gas sensitive element is physically changed to cause phase change of an interdigital electrode, a changed signal is transmitted to a detection circuit through a probe, the detection circuit transmits a detection signal to a node controller after processing, and the node controller transmits detected CO to a node controller through a wireless network₂Transmitting the gas concentration data to the monitoring terminal, and the monitoring terminal transmits all the diffused CO₂Detecting CO measured by a node₂The gas concentration is stored and analyzed, and the monitoring terminal is used for storing and analyzing the same diffused CO₂The concentrations of the detection nodes measured at different times form a group, and the concentration is measured for single diffusion type CO₂The concentration measured in a period of time at the detection node is subjected to normal distribution test toAnd performing sliding variance analysis on every 10 concentration data serving as a data segment, then finding out the data segment with obvious difference by using F statistic, thereby finding out a time segment with the maximum concentration change in a group, and if the concentration variance in the time segment is greater than a set threshold, displaying an analysis result by the monitoring terminal and sending alarm information.

The invention has the advantages of spatialization of CO₂The concentration analysis function, the analysis result is more reliable and directly perceived, possesses unusual alarming function simultaneously, is convenient for the staff in time to pay close attention to and make the processing.

The invention has the beneficial effects that: can be used for CO in a larger area₂Continuously monitoring the change of gas concentration by square difference analysis and normal distribution test to determine CO in the region₂The condition of gas concentration change alarms and reminds abnormal points, and the problem of existing wide-area gas concentration monitoring analysis dispersion is solved. The invention takes a surface acoustic wave dual-channel sensor as diffusion type CO₂The core of the detection node is a sensor prepared by an oxide composite film and an oxide-polymer composite gas-sensitive film, the sensor takes diffused gas induction and shallow buried soil as detection modes, water and dust are filtered by a hydrophobic breathable film, detection is not required to be carried out by air suction, the gas balance state of a detection environment is not damaged, continuous real-time detection can be carried out, time recovery is not required, the sensitivity of a gas-sensitive element of the sensor is high, and the requirements of low cost, long distance and wide-range detection are met.

Drawings

FIG. 1 is a schematic diagram of a system connection structure according to the present invention.

Fig. 2 is a schematic diagram of a dual channel structure sensor according to the present invention.

FIG. 1. diffusion type CO₂The system comprises a detection node, 2 a node controller, 3 a monitoring terminal, 4 a dual-channel structure sensor, 5 a detection circuit, 6 a piezoelectric layer, 7 an interdigital electrode, 8 a gas sensitive element, 9 a reference element, 10 a hydrophobic and breathable film, 11 a power supply module and 12 a GPRS communication module.

Detailed Description

The technical scheme of the invention is further specifically described by the following embodiments and the accompanying drawings.