Research On Key Technology Of Self-powered Pollutant Gas Wireless Sensor Monitoring Network

Industrial pollutant gas emissions are an important source of air pollution.In recent years,the state has continuously promoted air pollution prevention and control actions,and has listed the comprehensive management of air pollution in industrial enterprises as a key concern.Timely and effective monitoring of toxic and harmful gases in industrial pollution sources is a key link in the realization of pollution prevention and control,and therefore has attracted great attention.Existing gas sampling-detection methods have the advantages of high accuracy and reliable detection results,but they are time-consuming and poor in real-time,and are not suitable for real-time monitoring of the on-site emission;although large-scale online monitoring instruments realize real-time online monitoring,and the monitoring accuracy is high,However,it is expensive and cannot meet the requirements of large-scale and high-density monitoring.To this end,this subject is oriented to the needs of polluting gas emission monitoring in chemical industrial parks.Based on the narrowband Internet of Things technology,it carries out research on wireless gas sensor monitoring networks,and conducts in-depth research on environmental energy harvesting technology,wireless sensor terminal node design,and south and north application design.Complete the design and production and performance test of the wireless sensor monitoring system.The main research contents of the thesis are as follows:（1）Analyzed the research background of self-powered wireless sensor networks,systematically explained the research status and development trends of environmental energy harvesting and wireless sensor networks at home and abroad,and determined the main research content of this thesis.According to the monitoring requirements of the chemical park,designed the overall plan.（2）Researched and analyzed the conversion mechanism of environmental energy such as solar energy and thermoelectric energy,and conducted experimental research on the output characteristics of thin-film solar cells and TEG thermoelectric energy collectors.Based on this,a two-level environmental energy management circuit was designed to achieve collection and management of 570 m V solar cell energy and as low as 20 m V TEG energy,as well as charge and discharge management of energy storage components.（3）The analysis and selection of four types of gas sensors,main control chip and wireless communication chip including NH₃,SO₂,TVOC,H₂S,etc.have been completed,and the main control circuit,wireless communication module,NB-Io T antenna,etc.have been studied in depth.Designed and manufactured a wireless gas sensing terminal.（4）Designed procedures for southbound equipment and northbound applications.The program in the southbound device runs on the Lite OS real-time operating system to complete gas concentration detection and wireless data uplink transmission.The program in the northbound application receives and processes the uplink data to realize data visualization and data storage.（5）Establish a test platform to test the self-powered wireless gas sensor system.The30-day field test showed that the system can monitor the polluted gas in the park in real time.When the self-powered module is working normally,the power retention rate of the lithium battery after 30 days is 93.1%.