Design And Realization Of Multi-parameter Flue Gas Concentration Monitoring System

Air pollution is closely related to people’s physical and mental health.With the rapid development of China’s economy,environmental protection has been paid more and more attention.For the protection of the atmospheric environment,the most important thing is to do a good job in the monitoring of the flue gas discharged from the solid pollution sources.The design of multi parameter flue gas online monitoring system has important practical significance for the monitoring of flue gas emissions.In this thesis,flue gas monitoring system is designed by NDIR,which can realize the real-time and rapid measurement of SO2 and NO in flue gas.Based on Lambert-Beer’s law,this thesis adopts NDIR dual channel detection method to design the flue gas monitoring system,and completes the optical path design including infrared light source,gas chamber design and detector selection.Aiming at the problem of weak signal of infrared light source,ALD technology is used to coat the wall of the gas chamber to realize optical signal enhancement.Stm32f103c8t6 single chip is used as the main control chip including the design of data acquisition and data processing circuits such as light source driving circuit,signal processing circuit,etc.QT is used to write the corresponding upper computer processing system.Finally,the zero calibration of the whole flue gas monitoring system is carried out,and the relationship between the output voltage of the detector and the corresponding gas concentration is obtained by measuring standard concentration of different components.Through the analysis of the measurement data,the mutual interference between SO2 and NO in the flue gas is corrected,and the prototype is completed,and the field installation and the measurement experiment of the flue gas are carried out.The experimental results show that the relative error of the flue gas monitoring system is 5%,the repeatability and stability are within±1%.