Transmission Characteristics Of Microwave Radiation And Fire Detectors Simulation Design Under Fire Environment

In recent years,the frequent fire has brought great threats to people's life and property security.At present,the fire warning and detection methods are varied,but the environment of the fire is very complex.The smoke and water vapor has great influence on the infrared and optical detection methods,and it is difficult to detect the fire point accurately under the condition of smoldering.Microwave radiation detection uses the characteristics of the material's own radiation to detect,not only to a certain penetration of water vapor and cover,but also not sensitive to the effect of smoke.Therefore,it is expected to be an effective supplementary detection method.In this thesis,in the early stage of the typical fire burning material environment radiation characteristics research,the influence of microwave radiation in the atmosphere and smoke in the fire environment is further studied,and the simulation design of microwave radiation detector is also studied.The specific research is as follows:First,on the basis of atmosphere,water vapor,smoke in fire environment,the influence of atmosphere,water vapor and smoke on the transmission of microwave radiation in the fire field is calculated by using the molecular spectral line and Mie scattering theory,and the radiation transmission characteristics of the fire environment are obtained.At the same time,the extinction coefficient of the infrared band is compared,and the calculated results are verified by smoke radiation transfer experiment.Then,based on the radiation characteristics of two typical combustion materials,wood and polyurethane,combined with the influence of the smoke on the microwave radiation transmission under the fire environment,the parameter design of the reception frequency,spatial resolution,the sensitivity and other parameters of the fire spots of the typical combustion materials in the fire environment are selected and the imaging system is selected.Finally,the design of the hardware circuit of the detector is simulated based on ADS,which lays the foundation for the development of fire detector in the fire environment.