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基于复合喷动烟气净化工艺的反应塔流动特性研究
Study on Flow Field Characteristics of Purification Absorber Based on Multi-Spouted Flue Gas Purification Technology
【作者】 王雪;
【导师】 高继慧;
【作者基本信息】 哈尔滨工业大学 , 热能工程, 2009, 硕士
【摘要】 复合喷动烟气净化技术是以半干法烟气脱硫工艺为基础发展起来的可实现多种污染物协同脱除的新型烟气净化技术。该工艺的典型特征在于采用多级喷动塔体结构,通过分级分段,在一级塔体内进行以高速流化、液相吸收反应、催化转化过程为主的烟气净化工艺。在二级塔体内形成低速流化,形成高浓度含湿颗粒的内循环,通过湍流团聚和化学团聚机理对超细颗粒物进行团聚,在一级吸收净化的基础上实现高效烟气污染物联合脱除。本文开展复合喷动塔的气相流场以及气固两相流场研究,通过实验和数值模拟相结合的方法深入了解反应塔内的流动特性。可为复合喷动烟气净化塔的工业化设计和运行参数优化提供借鉴。根据相似模化的原理建立了风量为1500m3/h复合喷动冷态试验台,采用恒温热线热膜流速仪对反应塔的流动特性进行了研究。在反应塔全场流动特性分析的基础上,对竖直导流板、弯管导流板以及壁面钝体等内构件对一级塔体流场分布特性的影响进行了试验研究。研究显示与竖直导流板和弯管导流板相比,合理布置壁面钝体可以达到更好的使流场均匀的效果。通过壁面钝体的合理布置,可以实现对复合喷动塔一级塔体流场的控制与优化。利用FLUENT软件作为计算平台,对复合喷动烟气净化装置内的气固两相流动进行模拟,首先通过模拟结果与相关实验结果对比分析,选择了合适的湍流模型和气固两相流模型以及边界条件,其中气相湍流流动采用可实现的k-ε双方程模型,气固两相流动采用随机轨道模型。在此基础上对反应塔的气固流动行为进行了研究,主要研究了塔顶结构、入口弯管方向、雨披式导流部件、内构件组合对二级塔体颗粒内循环效果的影响。
【Abstract】 Multi-Spouted Flue Gas Purification technology is a newly developed flue gas purification technology based on MS-FGD(Multi-Spouted Flue Gas Desulfuriztion).With the multi-level structure, chemical absorption and submicron particles agglomeration can be realized in one absorber. The first level of the absorber is the gas-liquid main reaction zone, and the second level of the absorber is the gas-particle main reaction zone. Air flow field and gas- solid flow field of the Multi-Spouted Flue Gas Purification Absorber were studied with experiment and numerical simulation method.A cold aerodynamic rig was designed and build to study the air flow field of the Multi-Spouted Flue Gas Purification Absorber with IFA300. On the base of the study on the absorber, the influence of inner component with different structure to the flow field were studied. According to the results, the first level of the absorber was optimized. The study shows that with the right inner component, the flow field of the first level of the Multi-Spouted Flue Gas Purification Absorber can be controlled and optimized.Numerical simulation of the gas- solid flow field of the Multi-Spouted Flue Gas Purification Absorber was performed on CFD (Computational Fluid Dynamics) software platform. In the numerical simulation of absorber process, the Realizable k-εtwo equations turbulent model was used to simulate the turbulence. The stochastic tracking model was applied to analyze the gas-solid flow field. The comparison between the simulation and the experiment result shows a good agreement. The flow field and the distribution of gas-solid flow field in the absorber were gained and studied. Different structure was studied to optimize the second level of the absorber and to enhance particle internal circulation.
【Key words】 flue gas Purification; Multilevel Spraying; flow field analyzing; numerical simulation;