WO2021135855A1

WO2021135855A1 - Distributed air quality monitoring device and monitoring method thereof

Info

Publication number: WO2021135855A1
Application number: PCT/CN2020/134492
Authority: WO
Inventors: 刘付鹏; 王辅宋; 刘文峰; 谢镇; 李松; 郝文哲; 邹全锦; 龚健; 张志文
Original assignee: 江西飞尚科技有限公司
Priority date: 2019-12-30
Filing date: 2020-12-08
Publication date: 2021-07-08
Also published as: CN111122667A

Abstract

A distributed air quality monitoring device and a monitoring method thereof, which are applied to urban air monitoring networks and regional environment monitoring industries. The distributed air quality monitoring device comprises a microcontroller (12), a PM2.5 measuring module (1), a PM10 measuring module (9), an SO2 measuring module (2), an NO2 measuring module (11), a CO measuring module (16), an O3 measuring module (10), a VOCs measuring module (13), and a temperature and humidity measuring module (3); the PM2.5 measuring module (1), the PM10 measuring module (9), the SO2 measuring module (2), the NO2 measuring module (11), the CO measuring module (16), the O3 measuring module (10), the VOCs measuring module (13), and the temperature and humidity measuring module (3) are connected to the microcontroller (12); the SO2 measuring module (2), the NO2 measuring module (11), and the CO measuring module (16) use electrochemical gas measuring modules, and the PM2.5 measuring module (1) and the PM10 measuring module (9) use dust measuring modules based on a laser diffraction principle.

Description

Distributed air quality monitoring device and monitoring method

Technical field

The invention relates to a distributed air quality monitoring device and a monitoring method thereof, which are applied to urban air monitoring networks and regional environmental monitoring industries.

Background technique

The function of the air station is to conduct fixed-point, continuous or regular sampling, measurement and analysis of pollutants in the atmosphere and air. In order to monitor the air, several air stations are generally set up in a key environmental protection city, and multi-parameter automatic monitoring instruments are installed in the stations for continuous automatic monitoring. The monitoring results are stored in real time and analyzed to obtain relevant data. The air quality monitoring station is a basic platform for air quality control and reasonable assessment of air quality, and an infrastructure for urban air environmental protection.

At present, in accordance with the requirements of the standards and specifications, there are certain requirements for the performance indicators and continuity of the national standard air monitoring station. Therefore, the complexity of the system, the hardware cost, and the implementation cost are relatively large, and it is difficult to achieve full coverage and rapid implementation. Therefore, this type of monitoring system is mostly used at national and provincial monitoring sites.

With the rapid development of my country's economy, the problem of environmental pollution has become increasingly prominent. Although the state invests hundreds of billions of yuan in environmental governance every year, the effect is not obvious. In order to trace the distribution area of pollution sources, regional and local management agencies also need a regional environmental monitoring and cost-effective implementation plan. Based on the "point" layout of national standard monitoring stations, a distributed and regional monitoring system is added.

"Professional-level" monitoring systems such as traditional national standard monitoring stations are too expensive (a single set of equipment and construction costs exceed 1 million yuan), which is not conducive to mass promotion and grid deployment. Therefore, the current market demand for low-cost, simple installation and maintenance, suitable for batch, grid-based monitoring products is gradually increasing.

In summary, for regional management units, mastering the atmospheric environment and water environment in their respective jurisdictions, as well as understanding the "paths" of the formation of pollution sources, are one of the key contents that managers should master. Each management unit also urgently needs a more easy to implement and effective monitoring system to achieve. Therefore, in recent years, a grid-based atmospheric monitoring system has been proposed on the market, which realizes the digital management of the sources and dynamic changes of atmospheric pollutants in various areas through the construction of a regional monitoring sensor network. The "quasi-professional level" monitoring system can analyze the concentration changes based on the data of multiple pollutants monitored by the sensor terminal, and form the pollution tracking and transboundary transportation analysis report of hour, day, week and month, so as to realize the air pollution in the region and the city. The trend analysis of the temporal and spatial dynamics of the concentration of substances provides a direct basis for environmental law enforcement and decision-making.

Through the grid monitoring system, the collected data can be superimposed, compared, analyzed, and calibrated with the existing standard station monitoring sites, and the two are combined to generate a spatio-temporal dynamic trend chart to obtain high-density and high-frequency atmospheric particulate matter concentrations in the entire region The monitoring data is screened, calibrated, statistically analyzed, and dynamic graph drawing is carried out based on the background data analysis system to realize the analysis of the temporal and spatial dynamic change trend of atmospheric particulate matter concentration in the entire region, thereby determining the source of pollution and tracing the trend of pollutant diffusion. It has the greatest degree of supervision over pollution sources, and provides data and analysis basis for environmental law enforcement and decision-making.

To sum up, compared with the state-controlled sites, this demanded product is a low-cost, small-sized, easy-to-install and deploy monitoring system. The measurement performance meets the atmospheric monitoring level. The number of deployments, data analysis, etc. can be used to prevent air pollution. Judge the route and formation route, and trace the pollution source.

Summary of the invention

The technical problem to be solved by the present invention lies in the following three points: (1) Realize wireless real-time data transmission; (2) It can complete the measurement of conventional air quality parameters, temperature and humidity and other parameters, and can realize the over-value early warning function; (3) It has the function of using positioning information, automatic reading, and low-power battery power supply for the monitor.

The design of the present invention is mainly composed of air quality electrochemical module, MCU, temperature and humidity sensor, PM air measurement module, GPS positioning module, wireless transmission module, lithium battery, real-time clock, FLASH and other functional modules. The basic principle is: the system is composed of lithium The power supply of the system is realized by battery power supply and solar panel charging. The equipment wakes up according to the timing function of the real-time clock, collects the measurement data of various air quality modules during work, and transmits the data through the wireless module and backs up the data. The system does not rely on external power supply and transmission systems, so it can realize distributed installation and is a new type of air quality monitoring system.

To solve the above technical problems, the present invention adopts the following technical solutions:

A distributed air quality monitoring device, which includes a micro-controller, PM2.5 measurement module, PM10 measurement module, SO2 measurement module, NO2 measurement module, CO measurement module, O3 measurement module, VOCs measurement module, temperature and humidity measurement module ；

The PM2.5 measurement module, PM10 measurement module, SO2 measurement module, NO2 measurement module, CO measurement module, O3 measurement module, VOCs measurement module, and temperature and humidity measurement module are connected to a microcontroller;

Among them, SO2 measurement module, NO2 measurement module, CO measurement module adopt electrochemical gas measurement module, PM2.5 measurement module, PM10 measurement module adopts the dust measurement module of laser diffraction principle;

PM2.5 measurement module is a module used to achieve PM2.5 dust measurement;

PM10 measurement module is used to realize PM10 dust measurement module;

SO2 measurement module is a module used to measure the concentration of sulfur dioxide in the atmosphere;

NO2 measurement module is used to measure the concentration of nitrogen dioxide in the atmosphere;

CO measurement module is used to measure the concentration of carbon monoxide in the atmosphere;

O3 measurement module is a module used to measure the concentration of ozone in the atmosphere;

VOCs measurement module is used to measure volatile organic compounds in the atmosphere;

Temperature and humidity measurement module is a module used to measure atmospheric temperature and air temperature and humidity;

The above 8 types of measurement modules are all TTL-level digital interfaces, and they have built-in signal acquisition and conversion circuits. The external processor can read data according to its communication protocol to realize the data of each measurement parameter. TXD and RXD in each module The interface is connected to the microcontroller.

Furthermore, this monitoring device is designed with a GPS module, which is used for the positioning of the monitor, and automatically reads the GPS information during collection, without the need for manual input of location information;

NB-IOT transmission module and GPRS transmission module realize the data interaction function between the monitor and the remote platform.

Further, the monitoring device is designed with a lithium battery and a portable solar panel, and the lithium battery is connected with the portable solar panel.

Further, the monitoring device is designed with a real-time clock module and a data storage module.

A monitoring method of a distributed air quality monitoring device, characterized in that the steps of the method are:

1) The TXD and RXD pins of PM2.5 measurement module, PM10 measurement module, SO2 measurement module, NO2 measurement module, CO measurement module, O3 measurement module, VOCs measurement module, temperature and humidity measurement module are connected to the GPIO of the microcontroller Port.

2) GPS module, NB-IOT transmission module, and GPRS module are respectively connected to DC5V power supply, and the data interface is respectively connected to the UART1, UART2, and UART3 ports of the microcontroller;

3) Real-time clock RTC and data storage FLASH are respectively connected to the IIC interface and SPI interface of the microcontroller;

4) The above circuit modules are designed in a bottom PCB, and the lithium battery has its own charge and discharge management circuit function. The lithium battery is connected to the bottom PCB through the connecting terminal, and the 5V solar panel is connected to the charging port of the lithium battery. Realize the function of charging.

5) After the hardware is powered on, the initialization operation will be carried out. The main content of the operation is to initialize the port information and obtain the timing work interval information in the configuration memory as the frequency information of the subsequent work;

6) After the initialization is over, the data will be collected, and the data of PM2.5 measurement module, PM10 measurement module, SO2 measurement module, NO2 measurement module, CO measurement module, O3 measurement module, VOCs measurement module, temperature and humidity measurement module will be collected Polling and collecting once, and obtain data information according to the communication protocol of its module;

7). After obtaining the data information, read the backup data in the memory, pack it together and upload it via GPRS. If the upload is successful, the platform will send a confirmation message. After confirming that the platform accepts, the device will configure each module to low Power consumption mode, reduce power consumption, and sleep until the RTC generates the next interrupt signal. If the platform does not send a reception confirmation message, it is deemed that the data has not been uploaded normally, and the collected data needs to be backed up locally until the next After the second collection, upload data to prevent data loss;

8). System work is switched between work and low power consumption by the alarm interrupt generated by RTC.

The basic principle is: the system is powered by lithium batteries and charged by solar panels. The equipment wakes up according to the timing function of the real-time clock, collects the measurement data of various air quality modules during work, and transmits the data through wireless Modules are used for transmission and data backup. The system does not rely on external power supply and transmission systems, so distributed installation can be realized. It is a new type of air quality monitoring system.

The air quality measurement module is to realize the measurement function of each parameter gas. The ZE12 electrochemical module model is used, which uses electrochemical principles to detect CO, SO2, NO2, O3 and other gases in the air, which has good selectivity and stability. The built-in temperature sensor can be used for temperature compensation; it has both digital output and analog voltage output, which is convenient to use.

Its function is to measure the concentration of suspended solids in the air, using the ZH03B module, which uses the principle of laser diffraction to detect dust particles in the air, with good consistency, stability, and serial output. The measuring range is 0～1000ug/m3, and the minimum resolution particle diameter is 0.3μm. The working current is 120mA, the standby current is 20mA, and the working voltage is 5V.

The function of VOCs is to measure the concentration of volatile organic compounds. The method used is the photoionization module ZI01, which is a high-performance PID series module, which uses photoionization gas sensors and high-performance microprocessors, and uses ultraviolet light generated by ion lamps. The target gas is irradiated and bombarded, and the target gas will be ionized after absorbing enough ultraviolet light energy. By detecting the tiny current generated after the gas is ionized, the concentration of the target gas can be detected.

Position the monitoring equipment and upload the position information to facilitate the platform to display the position. The standard GPS module is adopted for implementation. The module has a positioning accuracy of 2.5mCEP, a working power supply of 3.3V, and a working current of 10mA.

Considering the complicated site conditions of the system during the design, it is difficult to guarantee the protection after wiring and the reliability of power supply. Therefore, this monitor is designed to be powered by a lithium battery to completely solve the problem of on-site power supply. At the same time, the system has a built-in wireless data transmission module, which solves the problem of data transmission and realizes the wirelessization of the system. In order to realize real-time measurement, the system control part can realize automatic control, and a supporting protective box is designed to ensure that the system can be used normally outdoors, but it can realize distributed installation. The equipment shell is realized by waterproof box and louvered box. The structure is integrated. The gas detection module is placed inside the tower louvered box, and the controller, transmission module, battery pack, etc. are placed inside the waterproof box.

In summary, through the design of each module, the monitor of the present invention adopts low power consumption design, built-in battery, wireless transmission, etc., to realize a low-cost, small-sized, easy-to-install and deploy monitoring device and method thereof. The performance meets the level of atmospheric monitoring. It is a monitoring device that can judge the path of atmospheric pollution and the formation of the path through the number of deployments, data analysis, etc., and trace the source of pollution.

Description of the drawings

Figure 1 is a functional block diagram of the air quality monitoring device of the present invention;

Figure 2 is a flowchart of hardware work of the present invention;

Figure 3 is a circuit design diagram of the MCU of the air quality monitoring device of the present invention;

Figure 4 is a FLASH circuit design diagram of the air quality monitoring device of the present invention;

Figure 5 is the RTC design diagram of the air quality monitoring device of the present invention;

Figure 6 is the design of the lithium battery charging circuit of the present invention;

Fig. 7 is a circuit design diagram of each measurement module of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings:

A distributed air quality monitoring device, which includes a micro-controller 12, a PM2.5 measurement module 1, a PM10 measurement module 9, a SO2 measurement module 2, a NO2 measurement module 11, a CO measurement module 16, an O3 measurement module 10, and VOCs Measurement module 13, temperature and humidity measurement module 3;

The PM2.5 measurement module 1, the PM10 measurement module 9, the SO2 measurement module 2, the NO2 measurement module 11, the CO measurement module 16, the O3 measurement module 10, the VOCs measurement module 13, and the temperature and humidity measurement module 3 are connected to the microcontroller 12 ；

Among them, SO2 measurement module 2, NO2 measurement module 11, and CO measurement module 16 use electrochemical gas measurement modules, PM2.5 measurement module 1, PM10 measurement module 9 use laser diffraction principle of dust measurement module;

PM2.5 measurement module 1 is a module used to realize PM2.5 dust measurement;

PM10 measurement module 9 is a module used to realize PM10 dust measurement;

SO2 measurement module 2 is a module for measuring the concentration of sulfur dioxide in the atmosphere;

NO2 measurement module 11 is a module for measuring the concentration of nitrogen dioxide in the atmosphere;

The CO measurement module 16 is a module for measuring the concentration of carbon monoxide in the atmosphere;

The O3 measurement module 10 is a module for measuring the concentration of ozone in the atmosphere;

VOCs measurement module 13 is a module for measuring volatile organic compounds in the atmosphere;

The temperature and humidity measurement module 3 is a module for measuring atmospheric temperature and air temperature and humidity;

This monitoring device is designed with GPS module 4, which is used for the positioning of the monitor. It automatically reads the GPS information during collection without manual input of location information. In addition to data collection, the monitor can realize automatic The functions of positioning, wireless data transmission, and low-power power supply can be applied to multiple scenarios.

The NB-IOT transmission module 5 and GPRS transmission module 6 realize the data interaction function between the monitor and the remote platform.

The monitoring device is designed with a lithium battery 8 and a portable solar panel 15, and the lithium battery 8 is connected to the portable solar panel 15. This device is a low-power monitoring device with a built-in lithium battery as a system power source, which improves the practicability of the system.

The monitoring device is designed with a real-time clock module 7 and a data storage module 14. This device is a low-power monitoring device that works intermittently through a regular working mode and automatically stores data.

A monitoring method of a distributed air quality monitoring device, the steps of the method are:

1. PM2.5 measurement module 1, PM10 measurement module 9, SO2 measurement module 2, NO2 measurement module 11, CO measurement module 16, O3 measurement module 10, VOCs measurement module 13, temperature and humidity measurement module 3 TXD, RXD pins Connect to the GPIO port of the microcontroller.

2. GPS module 4, NB-IOT transmission module 5, and GPRS module 6 are respectively connected to DC5V power supply, and the data interface is respectively connected to the UART1, UART2, and UART3 ports of the microcontroller 12;

3. Real-time clock RTC7 and data storage FLASH14 are respectively connected to the IIC interface and SPI interface of the microcontroller;

4. The above circuit modules are designed in a bottom PCB, and the lithium battery 8 has its own charge and discharge management circuit function. The lithium battery is connected to the bottom PCB through the connection terminal, and the 5V solar panel is connected to the charging port of the lithium battery. Realize the function of charging.

5. After the hardware is powered on, the initialization operation will be carried out. The main content of the operation is to initialize the port information and obtain the timing work interval information in the configuration memory as the frequency information of the subsequent work;

6. After the initialization is over, the data will be collected. PM2.5 measurement module 1, PM10 measurement module 9, SO2 measurement module 2, NO2 measurement module 11, CO measurement module 16, O3 measurement module 10, VOCs measurement module 13, The data of the temperature and humidity measurement module 3 is polled and collected once, and the data information is obtained according to the communication protocol of the module;

7. After obtaining the data information, read the backup data in the memory, package them together and upload them via GPRS. If the upload is successful, the platform will send a confirmation message. After confirming that the platform accepts, the device will configure each module as low power Consumption mode, reduce power consumption, and sleep until the RTC generates the next interrupt signal. If the platform does not send a reception confirmation message, it is deemed that the data has not been uploaded normally, and the collected data needs to be backed up locally until the next time. After collection, upload data to prevent data loss;

8. System work is switched between work and low power consumption by the alarm interrupt generated by RTC.

Its function is to measure the concentration of suspended solids in the air, using the ZH03B module, which uses the principle of laser diffraction to detect dust particles in the air, with good consistency, stability, and serial output. The measuring range is 0～1000ug/m ³ , and the minimum resolution particle diameter is 0.3μm. The working current is 120mA, the standby current is 20mA, and the working voltage is 5V.

Considering the complicated site conditions of the system during the design, it is difficult to guarantee the protection after wiring and the reliability of power supply. Therefore, this monitor is designed to be powered by a lithium battery to completely solve the problem of on-site power supply. At the same time, the system has a built-in wireless data transmission module, which solves the problem of data transmission and realizes the wirelessization of the system. In order to realize real-time measurement, the system control part can realize automatic control, and a supporting protective box is designed to ensure that the system can be used normally outdoors, but it can realize distributed installation. The equipment shell is realized by waterproof box and louver box. The structure is integrated. The gas detection module is placed inside the tower louver, and the controller, transmission module, battery pack, etc. are placed inside the waterproof box.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. And variations, the scope of the present invention is defined by the appended claims and their equivalents.

Claims

A distributed air quality monitoring device, which is characterized in that it includes a micro-controller (12), a PM2.5 measurement module (1), a PM10 measurement module (9), a SO2 measurement module (2), and a NO2 measurement module ( 11) CO measurement module (16), O3 measurement module (10), VOCs measurement module (13), temperature and humidity measurement module (3);

The PM2.5 measurement module (1), PM10 measurement module (9), SO2 measurement module (2), NO2 measurement module (11), CO measurement module (16), O3 measurement module (10), VOCs measurement module ( 13) Connect the temperature and humidity measurement module (3) to the microcontroller (12);

Among them, SO2 measurement module (2), NO2 measurement module (11), CO measurement module (16) adopt electrochemical gas measurement module, PM2.5 measurement module (1), PM10 measurement module (9) adopt laser diffraction principle for dust measurement Module

PM2.5 measurement module (1) A module used to realize PM2.5 dust measurement;

PM10 measurement module (9) is a module used to realize PM10 dust measurement;

SO2 measurement module (2) is a module used to measure the concentration of sulfur dioxide in the atmosphere;

NO2 measurement module (11) is a module for measuring the concentration of nitrogen dioxide in the atmosphere;

CO measurement module (16) is a module for measuring the concentration of carbon monoxide in the atmosphere;

O3 measurement module (10) is a module for measuring the concentration of ozone in the atmosphere;

VOCs measurement module (13) is a module for measuring volatile organic compounds in the atmosphere;

Temperature and humidity measurement module (3) A module for measuring atmospheric temperature and air temperature and humidity;

The above 8 types of measurement modules are all TTL-level digital interfaces, and they have built-in signal acquisition and conversion circuits. The external processor can read data according to its communication protocol to realize the data of each measurement parameter. TXD and RXD in each module The interface is connected to the microcontroller.
The distributed air quality monitoring device according to claim 1, characterized in that: the monitoring device is designed with a GPS module (4), which is used for the positioning of the monitor, and automatically reads the GPS information during collection without manual input of the location. Information

The NB-IOT transmission module (5) and GPRS transmission module (6) realize the data interaction function between the monitor and the remote platform.
The distributed air quality monitoring device according to claim 1, characterized in that: the monitoring device is designed with a lithium battery (8) and a portable solar panel (15), lithium battery (8) and a portable power supply The solar panel (15) is connected.
The distributed air quality monitoring device according to claim 1, characterized in that: the monitoring device is designed with a real-time clock module (7) and a data storage module (14).
A monitoring method for a distributed air quality monitoring device according to claims 1-4, characterized in that the steps of the method are:

A) PM2.5 measurement module (1), PM10 measurement module (9), SO2 measurement module (2), NO2 measurement module (11), CO measurement module (16), O3 measurement module (10), VOCs measurement module (13). The TXD and RXD pins of the temperature and humidity measurement module (3) are connected to the GPIO port of the microcontroller;

B), GPS module (4), NB-IOT transmission module (5), GPRS module (6) are respectively connected to DC5V power supply, and the data interface is respectively connected to the UART1, UART2, and UART3 ports of the microcontroller (12);

C), real-time clock RTC (7), data storage FLASH (14) are respectively connected to the IIC interface and SPI interface of the microcontroller;

D). The above circuit modules are designed in a bottom PCB, and the lithium battery (8) has its own charge and discharge management circuit function. The lithium battery is connected to the bottom PCB through the connection terminal, and the 5V solar panel is charged with the lithium battery. The port is connected to realize the charging function;

E) After the hardware is powered on, the initialization operation will be carried out. The main content of the operation is to initialize the port information and obtain the timing work interval information in the configuration memory as the frequency information of the subsequent work;

F). After the initialization is over, the data will be collected, about to be PM2.5 measurement module (1), PM10 measurement module (9), SO2 measurement module (2), NO2 measurement module (11), CO measurement module (16) , O3 measurement module (10), VOCs measurement module (13), temperature and humidity measurement module (3) polling and collecting data, respectively according to the communication protocol of the module to obtain data information;

G). After obtaining the data information, read the backup data in the memory, pack it together and upload it via GPRS. If the upload is successful, the platform will send a confirmation message. After confirming that the platform accepts, the device will configure each module to low Power consumption mode, reduce power consumption, and sleep until the RTC generates the next interrupt signal. If the platform does not send a reception confirmation message, it is deemed that the data has not been uploaded normally, and the collected data needs to be backed up locally until the next After the second collection, upload data to prevent data loss;

H). System work is switched between work and low power consumption by the alarm interrupt generated by RTC.