烟气微细颗粒表面特性及其复合凝并机理研究

The fine particles carried by coal-fired flue gas after wet desulfurization tower are important precursor of atmospheric haze, therefore studying the characteristics and laws of coagulation is of great significances to solve the problem of gypsum rain and PM2.5.By analyzing the composition of fine particles and surface/interface features,a swirling flow field will be established via the applicant's invention of the steam swirl ultrasonic atomization nozzle, thus in ultrasonic environment,the conditions of forming embryos and the coupling relationship between particles’ surface/interface characteristics can be experimentally studied,which is on dual influences of turbulence coagulation and vapor phase transition coagulation. Accordingly,surface nucleation, condensation and growing process of fine particles will be revealed,and the coagulation and growth model of fine particles will be established further.And then the coupling laws of particulate physical and chemical characteristics, initial particulate size, residence time, humidity and temperature of flue gas, turbulence of flue gas, and some other factors will be driven. Then, the coagulating competitive features as well as the characteristics of the critical factors of fine particles under wet steam environment will be researched.Next,combining with time-spatial features stemmed from multiple physical fields theory,the fluid turbulent eddy scale which has the most significant effect to coagulation will be explored.All these provide theoretic foundation to what will be used to achieve coordinating and enhancing coagulation of fine particles and promote the growth of the PM2.5 and removal of it.

通过湿法脱硫塔后的燃煤烟气携带的微细颗粒，是大气灰霾形成的重要前驱物。研究其特性及凝并规律对解决石膏雨及PM2.5问题具有重要意义。通过分析该微细颗粒的构成及表面/界面特征，采用申请者发明的蒸汽超声波雾化喷嘴构建旋流动力场，实验研究在湿蒸汽环境下湍流凝并和蒸汽相变凝并多重作用下微细颗粒形成晶胚的条件与颗粒物表／界面特性的耦合关系；揭示其表面晶胚成核、凝聚、长大的过程，进一步建立微细颗粒复合凝并生长模型，导出颗粒物化特性、初始粒径、停留时间、烟气湿度与温度、Re数等诸因素与颗粒凝并的耦合规律，寻找饱和湿蒸汽环境下微细颗粒凝并竞争特性及特征因子，结合多物理场耦合理论获得颗粒在空间凝并的时空特征，导出对凝并影响敏感度最大的颗粒特征尺度，为实现协同强化微细颗粒凝并及促使PM2.5粒度增大和脱除提供理论基础。

湿法脱硫塔后的烟气携带的微细颗粒，是大气灰霾形成的重要前驱物，研究其特性及凝并规律对解决石膏雨及PM2.5问题具有重要意义。为了揭示脱硫后烟气中微细颗粒的凝并机制，项目选取了火电厂燃煤烟气和冶金烧结烟气湿法脱硫塔后微细颗粒物作为研究对象，实验研究了该微细颗粒组成及特征，在超声波环境下应用饱和蒸汽及湍流作用，研究了其形成晶胚的条件，揭示了颗粒物相互凝聚、长大的过程；基于气-液两相流湍流理论，得到了颗粒物初始粒径、停留时间、湿度、Re等因素与颗粒凝并的耦合规律；建立了脱硫后烟气微细颗粒复合凝并模型，并在模型指导下研发了新型雾化及凝并专利装置，试验得到了复合凝并影响程度最大的流体湍流尺度和微细颗粒特征尺度，达到了项目书中提出的二个目标。. 项目共获得授权专利6项，其中欧洲发明专利1项、德国发明专利1项、中国实用新型专利4项；发表EI论文2篇；其他论文11篇；获广东省技术发明奖二等奖1项、国际发明展览会金奖1项、广东省专利奖银奖1项、广东省环境保护科学技术奖1项；培养博士研究生2名，硕士研究生14名；指导学生获全国大学生节能减排科技竞赛金奖1项、二等奖1项，获“互联网+”大学生创新创业大赛广东省赛金奖1项、广东大学生节能减排工业设计大赛一等奖1项，获杭州高价值知识产权创新创意大赛银奖1项、杭州“市长杯”优秀奖1项。. 除此以外，基于上述成果，还开发了旋流雾化器及凝并除雾器专利产品，并通过试验，实现了在脱硫塔中微细颗粒物的协同脱除，形成了“旋流雾化高效深度脱硫除尘一体化技术”成果。成果通过专利实施许可授权7家环保企业实施，应用于柳钢集团、江苏理文造纸有限公司、广东新明珠陶瓷集团、德国24.9MW大型集装箱船舶（IMO号：9431800）等行业大型烟气多污染物协同净化项目中，经第三方权威机构检测验证，达到了烟气超洁净排放。项目通过示范与推广，成功实现了产业化，为工业烟气超洁净粉尘治理提供了理论基础和一套全新的方法。