| Existing equipments in coal-fired power plant have less efficient removal of sub-micron particle (PM2.5), and a large number of sub-micron particle emitted into the atmosphere causing environmental pollution. At the same time, sub-micron particle can enrich a variety of heavy metal compounds, which will do more harm to human health and ecological environment. This brought about serious environmental pollution problem, which has aroused wide attention both at home and abroad. Because of the usage of chemical agglomeration, sub-micron particles are agglomerated, when they grow up, they will be removed away. And this opened up a new ideas that sub-micron particle matter emission control. In this paper, the chemical agglomeration micro-adsorption mechanism of sub-micron particles is simulated by the Monte Carlo algorithm, at the same time the flow field of agglomeration room is simulated by fluent, as well as gas - solid - liquid multi-phase flow Monte Carlo program.First of all, the process of solving agglomeration in Monte Carlo algorithm is analysed, and It boils down to three main steps: structure of the virtual agglomeration particles and droplets, to achieve sampling from the virtual agglomeration particles and droplets, and the estimate of particle size. After agglomeration is analysed, agglomeration kernel function is kown to contain adsorption kernel, fragmentation kernel, evaporation kernel. Besides, by analysing flocculation theory and agglomeration kernel function, distribution and immersion agglomeration mechanism are considered simultaneously, then agglomeration model will be bulided up.And then, the latest flocculation model of water treatment is choosed, Monte Carlo algorithm is also selected, and synchronously the two agglomeration mechanisms are considered to discuss the agglomeration flocculation process of micron particles which are belong to the three micron-areas. The change of particle size distribution, number and average diameter are researched. At the same time, the fragmentation impact on agglomeration is considered. The results show that, the chance of agglomeration for 0.1μm particles in the late agglomeration is smaller; Even the number of droplets is smaller, the chance of agglomeration for 1μm particles in the late agglomeration is smaller; For 2.5μm particles, agglomeration agent can not be too much traffic, otherwise the efficiency of agglomeration will be reduced.Finally, the turbulent flow model and the gas-liquid-solid multiphase flow model are applied to simulate the experimental agglomeration room and the agglomeration room of the actual power plant by fluent software respectively, in order to study the flow impact on agglomeration. In addition, in order to make up the impossibility of the agglomeration nuclear function being not added to fluent, the gas-liquid-solid multiphase flow program is editted by myself, to which the agglomeration nuclear function is added to study the agglomeration process in the actual flow. The results show that, within the recirculation zone below the nozzle in the agglomeration room, flue gas and droplets entrainment occurs, increasing the action time among particles and droplets, and enhance the effect of agglomeration. |
