摘要
为探究脱硫净烟气降温冷凝过程中可凝结颗粒物(condensable particulate matter,CPM)的脱除特性,基于模拟氨法脱硫试验台,采用数值模拟方法探究了换热器内过饱和水汽环境的形成规律;利用氟塑料毛细管换热器对脱硫净烟气进行降温冷凝,促进净烟气中CPM相态转化、凝结长大与脱除;并利用美国EPA(U.S.Environmental Protection Agency,U.S.EPA)方法202对换热器前后烟气中CPM的质量浓度进行采样测试,考察了净烟气降温冷凝过程中CPM的脱除性能。结果表明,典型工况下冷凝式换热器内烟气温降及水汽饱和度随流程长度的增加而增加,换热器内部可建立满足CPM相态转化、凝结长大的过饱和水汽场;同时,采用离子色谱仪对冷凝式换热器进出口烟气中CPM离子浓度测试,CPM主要由无机组分构成,其中以SO_(4)^(2-)和NH_(4)^(+)为主;降温冷凝过程中形成的过饱和水汽环境对CPM的脱除具有一定的促进作用,CPM的排放浓度可由38.09mg/m^(3)降至26.34mg/m^(3),脱除效率达30.84%。烟气降温冷凝方法有利于促进氨法脱硫净烟气中CPM减排,为工程实际应用提供了一定的理论依据。
In order to explore the removal characteristics of condensable particulate matter during the cooling and condensation process of desulfurization flue gas,this paper,based on the simulated ammonia desulfurization test bed,used fluorine plastic capillary heat exchanger for cooling and condensation of desulfurization net flue gas to promote the nucleation,coagulation and removal of condensable particulate matter in the desulfurization flue gas.The formation law of supersaturated water vapor environment in fluorine plastic capillary heat exchanger was studied by numerical simulation.The mass concentration of condensable particulate matter before and after the heat exchanger was tested by EPA Method 202,and the removal performance of condensable particulate matter in the desulfurization flue gas during the process of cooling and condensation was investigated.The results show that the cooling amplitude and water vapor saturation in the condensing heat exchanger increase with the increase of the process length under typical conditions.The fluorine plastic capillary heat exchanger can establish the supersaturated water vapor environment which is satisfying the condensable particulate matter condensation growth.At the same time,under the influence of gravity acceleration,the supersaturation at the bottom of the fluorine plastic capillary heat exchanger is higher,and the supersaturation at both sides of the fluorine plastic capillary heat exchanger wall is lower.Meanwhile,the concentration of condensable particulate matter ions in the import and export flue gas of condensing heat exchanger was measured by ion chromatograph.It is found that condensable particulate matter is mainly composed of inorganic components,among which SO_(4)^(2-) and NH_(4)^(+) are the main ones.The saturated water vapor environment formed during cooling and condensation can promote the removal of condensable particulate matter to a certain extent.The condensable particulate matter emission concentration can be reduced from 38.09mg/m^(3) to 26.34mg/m
作者
王磊磊
吴昊
王茜雯
杨宏旻
WANG Leilei;WU Hao;WANG Qianwen;YANG Hongmin(School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210023,China)
出处
《电力科技与环保》
2022年第2期142-149,共8页
Electric Power Technology and Environmental Protection
基金
国家自然科学基金项目(51806107)。
关键词
氨法脱硫
氟塑料毛细管换热器
可凝结颗粒物
降温冷凝
脱除
ammonia desulfurization
fluorine plastic capillary heat exchanger
condensable particulate matter
cooling and condensation
removal
