Ultra-low Power Consumption Urban Sewer Biogas Detection System

With the development of urban construction in our country,the scale of urban sewers is getting larger and larger.However,due to the particularity of the sewer environment,it is easy to produce and accumulate a large amount of biogas,which is flammable and explosive.When the concentration of biogas exceeds a certain level,it may explode,which will bring huge potential safety hazards to people’s lives.At present,the domestic detection methods for flammable and explosive gases are mostly catalytic combustion sensors.Such sensors generally have problems such as high power consumption,poor anti-interference,short life and so on.At the same time,due to the particularity of the sewer location,the purpose of real-time monitoring cannot be achieved.In order to ensure the safety of residents,it is essential to develop a sewer biogas detection system with low power consumption and strong real-time performance.In this paper,the composition of biogas is analyzed,and the detection method of combustible gas methane based on ultrasonic phase difference method and the detection method of carbon dioxide gas using infrared absorption sensor are determined through comparison.Aiming at the complex structural environment of the sewer,this paper proposes a design scheme of a low-power remote detection system based on wireless sensor network and wireless communication technology.The system consists of detection terminal,wireless communication module,coordinator,Internet of Things cloud platform,and Windows client.The detection terminal is responsible for the detection and data processing of the concentration of methane gas and carbon dioxide gas in the sewer,and the detection data is transmitted to the coordinator through the Zig Bee wireless communication module;the coordinator connects to the Internet through the Wi Fi wireless communication module,and uploads the data to the cloud platform through the HTTP protocol;the trigger settings of the cloud platform enable automatic email reminders when the monitoring data exceeds the threshold;using the data push of the cloud platform,the cloud platform is connected with the Windows client to realize the data transmission of the entire system.The functions of login registration,real-time data display,historical concentration query,over limit alarm notification,etc.are realized on the Web cloud platform and Windows client interface.Finally,the whole system was tested with standard concentration of gas in the laboratory environment.The experiment shows that the system meets the requirements of measurement accuracy and realizes the data monitoring function of cloud platform and client,and achieves the expected design goals.