Experimental Study On The Change Of Log Combustion Flue Gas With Water Mist Applying

In the northeast region of China, spring and autumn are windy, rainless and dry, so they are the peak period of forest fire. When the forest fire happens, it will cause a great damage to the forest resources and it is also a serious threat to the ecological security and human life. Forest fire will release a large amount of smoke with the rise of fire plume, its main components are CO2, some water vapor, CO, CxHy, NO, SO2 and dust grain with unburnt carbon particles. They seriously affect the ecological environment. These carbon particles and ash are released into the atmosphere with the fire plume and they often attach to the suspended particulate matter in the atmosphere, so the air will become more polluted and increase the formation probability of haze. Through the change regularity of the log combustion flue gas under the action of water mist, simulated the water mist’s effect on the forest fire smoke. Using the methods of theoretical analysis and experimental research, analyzed the change regularities of the log combustion flue gas under the action of water mist and got some basic theory and rules. It was meaningful to take appropriate measures to control the forest fires and smoke spread timely and effective. The main research contents and results of this paper are as follows:(1)In the aspect of theoretical analysis, analyzed the log combustion in theory, and provided theoretical basis for the characteristics of log combustion flue gas. According to the formation mechanism of water mist and the law of motion of smoke, combined with dynamics effect, cloud physics effect and transportation mechanism of Steffen flow, provided a theoretical basis for the experimental part.(2)In the aspect of experimental study, the log combustion experiment was carried out in the standard laboratory. In this experiment, the flue gas characteristic parameters in the combustion process were collected, and the log combustion heat flux and heat release rate were analyzed. Through the quantitative analysis of log combustion temperature field and smoke characteristics, studied the influence of different combustion conditions to the flue gas. By changing the effect time, working pressure and fan ventilation rate of water mist device, researched the change regularities of the heat release rate, heat flux and the concentration of CO2, CO, O2 in the log combustion under the action of water mist in different working conditions. By an indoor combustion experiment to the log, we researched the sedimentation of water mist to the log combustion smoke particles. By using the Sirion200 type electron microscope to scan the smoke particle samples, we obtained the change regularities of characteristic parameters dA and ps before and after the effect of water mist by statistical method. It was showed that the effect of air supply volume, water mist pressure and working time on the change of flue gas is great.