Research On Simulation Method And Testing Device Of Fog-haze

In recent years,the severe industrial pollution and exhaust emissions have led to an increase in the probability of haze weather,which has made the air quality of urban industrial parks and downtown areas deteriorated,has had a tremendous impact on the ecological natural environment and people's daily lives.However,the haze weather under natural environmental conditions is characterized by randomness and unpredictability that its parameters are changing at any time and cannot be controlled by humans,especially for the pollution flashover of power equipments.It's very difficult to be researched in depth and it is necessary to develop an experimental device to simulate fog-haze effectively.Therefore,the testing device should be constructed which can simulate different characteristics and conditions of fog-haze environment.Under the corresponding conditions of haze environment,the corresponding experiments are constructed and the corresponding data obtained can be used to study the formation mechanism of haze and to explore the deeper impact characteristics and mechanism of haze,especially for studying the influence of pollution flashover on electrical equipments.Firstly,the testing device is designed by Solidworks software,and then the internal cavity change were taken to the hydrodynamic simulation analysis by ANSYS FLUENT.The corresponding initial parameters and low velocities were set to simulate the characteristics of the wind speed changes in the device.The simulation results show that the wind speed in and around the gas dispersion ring is lower than but near the initial velocity,while the wind speed in other regions is almost 0m/s.This indicates that the internal environment of the testing device is stable and suitable as a simulated haze environment device.Then,we fabricated the cylindrical testing apparatus with the diameter of0.37m and the height of 1.17m using polymethyl methacrylate(PMMA),analyzed the selection of material and detection methods of simulated fog-haze,also discussed the formation of natural haze environment the realization method and generation of haze simulation.For the sampling of simulated smog materials,we selected the mixture of coal ash and soil as to simulate haze particles,selected the the water vapour generated by ultrasonic humidifier as the water mist while the particle concentration sensor was used to monitor the smog concentration and particle size distribution characteristics of the testing area,the thermohygrograph was used for measuring the temperature and humidity changes in the device.In the experiment,by controlling the humidification time and the amount of particulate matter and water mist particles per unit time,it successfully simulated the temperatures at 25±3?,relative humidity between 65%and 85%and the concentration of PM2.5 is in the range of 0-500?g/m~3.The detection devices and monitoring effect for the fog-haze testing device were detaily explained.On this basis,the haze environment under different conditions was established,and many experiments were carried out.The corresponding experimental data were compared,and the characteristics of the haze concentration and particle size distribution were analyzed and summarized.The experimental results show that the haze environments generated by the experimental device with three bottom blades can be more uniformly diffused in the device,and the concentration,aerosol particle size distribution,temperature and relative humidity can be close to the actual haze,with better stability and slower settling rate.It is suitable for the contamination experiment of simulated haze,AC flashover experiment and other aspects of research.