| With the rapid development of China’s shipbuilding industry during the ‘EleventhFive-Year’, to2013China has been the world leader in terms of deadweight tonnage (dwt)of ships built and has become a maritime power in the world. However, with the increase inthe number and tonnage of ships built, China’s shipwrecks each year are also increasing,especially ship fires that will cause huge casualties and property losses. According tostatistics, ship fire accounts for about11%of the total number of shipwrecks. Shippingvessels will carry a lot of mobile fuel, including diesel, gasoline, fuel oil, etc., which due tothe aging pipeline and other reasons is prone to leakage, causing fire. When a ship catchesfire, fuel and other combustibles in the cabin quickly produce large amounts of smoke andtoxic gases, hindering personnel escape and affecting firefighters entering the cabin to putdown the fire and rescue people. USA Navy warships in waste make experiments on thenano oxide and flue gas, the experimental results very well. But its mechanism has not beenreported smoking control. At present, the molecular dynamics have been widely used innano materials,large biological molecules, and has made many outstanding achievements.And based on summary of the many achievements, methods of interdisciplinary research,the interaction mechanism of metal oxide nanoparticles and smoke from the micro view,provides a new idea for the study of ship fire.This paper, aimed at reducing the smoke concentration, used a new nano-technology toachieve the purpose of smoke control, applying the adsorption properties ofnano-magnesium oxide particles in absorption of harmful gases and soot particles in thesmoke.Firstly, analyzing the morphology structure of the nano magnesium oxide, cubic shapenanometer magnesia in0nm~10nm range increases with the reduction of particle size ofspecific surface area increased rapidly, when the particle size is1nm surface atomic ratiocan reach above90%;Secondly, Study of the physical and chemical properties of flue gas, indicates that themain reason is that hinder people escape existed in the line of sight of the smoke particles influe gas and cause loss of ability to escape the poisonous gases CO, SO2and othermolecules. Thirdly, based on the theory of molecular dynamics simulation, using Lammps andMaterial Studio simulation software as a platform, established the0nm~10nm particle cubenano Magnesium Oxide model complete surface diameter and CO, SO2, CO2in the flue gasmolecules and carbon smoke particle model. Through the Lennard-Jones potential functionand key cooperation with potential function to establish mathematical model of the forcefield, nano Magnesium Oxide tobacco control mechanism from the micro perspective.Quantification of main technical parameters on tobacco control process, such as nanoMagnesium Oxide particle size, specific surface area, adsorption time, the adsorptionamount and temperature, after the simulation results obtained include:(1) Nano Magnesium Oxide can gas molecules and carbon smoke particles in flue gas;in a certain range with the increase of the diameter of nanometer Magnesium Oxide particle,adsorption time is shortened, the adsorption time was in the range of0nm~2nm;(2) Adsorption gas molecular weight with nano Magnesium Oxide particle sizeincreases and two party relationship;(3) Nnano Magnesium Oxide have obvious differences for different gas moleculesadsorption capacity, the number of adsorbed CO molecules is much higher than that of SO2molecules;(4) The CO molecules can form obvious double vertical adsorption, and C adsorptionenergy is greater than the end end O; SO2molecules can form a monolayer adsorption, andO adsorption energy is greater than the end S; in300K~400K temperature range, with theincrease of temperature of nano Magnesium Oxide adsorption gas molecular weightdecreased, but the decrease was not obvious; in a certain size range with the increase of theparticle diameter, nano Magnesium Oxide adsorption soot time has the same properties andgas absorption. However, there is no obvious rules with the change of temperature on theadsorption.Finally, considering the actual delivery of magnesium oxide nano particles on themovement of smoke in the air, analysis of fluid particles, particles in flue gas and the motionof gas molecules and by the integrated force, combined with the simulation results of nanoMagnesium Oxide adsorption gas, can obtain nano Magnesium Oxide can be harmful gasesand soot particles absorb smoke, with absorption and dissipation of flue gas, the resultsprovide theoretical basis for the nano particles in ship fire control. |
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