Effects Of External Radiative Heat Flux On The Combustion Behavior Of Porous Beds Soaked With Combustible Liquid

Combustible liquid such as gasoline can diffuse into solid or other porous materials due to leakage from accidental spillage or automobile collision. If an external heat source is close to the fuel layer, ignition can be triggered and subsequent flame spread controlled in a proper way, severe loss of human life and property damage can occur. It is of fundamental importance to study on effects of external radiative heat flux on the combustion behavior of porous beds soaked with combustible liquid in understanding combustion process, developing combustion theory and controlling the fire accidents, and protecting environment. In this thesis, effects of external radiative heat flux on the combustion behavior of porous beds soaked with combustible liquid were experimentally investigated..In the first chapter, the state of the arts of the combustion behavior of porous beds soaked with combustible liquid was reviewed. Based on the paper review, the topics of the thesis were proposed.In the second chapter, introductions on the experiment systems and data acquisition were presented.In the third chapter, effects of the external radiative heat flux on the combustion behavior of non-spread diffusion flame of liquid fuel soaked in porous beds were experimentally conducted. The effects of the different external heat flux on the combustion behavior of porous beds soaked with combustible liquid were firstly analyzed. The different radiative heat flux was obtained by changing the electrical power. The combustion behaviors, including the temperature variation in the porous beds, the gas-liquid coexisting zone moving speed combustion duration and fuel consumption rate, and so on, were presented. Meanwhile, a typical radiative heat flux was used to study the effects of the characteristics of porous materials on the combustion behavior of ethanol soaked in the beds. The porous materials of steel ball, sand and zeolite were respectively used. Furthermore, the porous material of sand with mean diameter of 0.9mm, 1.8mm, and 2.3mm was chosen to study the effects of the porous size on the combustion behavior. The effects of fuel properties on the combustion behavior under the external radiative heat flux were also presented in this thesis. Finally the combustion behavior of flame spread over the surface of the porous beds soaked with combustible liquire was experimentally studied. The experimental results are significant to the fire safety, the fine size porous is benefit to the control the fire, and the larger size porous is more conducive to the removal of the fuel to achieve clean of the soil.Finally, the summary and the further suggestions were presented in chapter 4.