基于烟气浓淡分离的袋式除尘器结构改进与流场优化模拟

Simulation on structural improvement and airflow optimization of bag filter based on flue-gas rich-iean separation

锅炉袋式除尘器存在流场不均匀和滤袋磨损的问题,为了解决这些问题,对袋式除尘器的结构与流场特性方面做出改进和优化。分析直吹式进气的袋除尘器进行流场特性,同时对进气结构进行烟气浓淡分离和横向扩张改造。利用FLUENT流体动力学计算(CFD)软件,进行气固两相三维流场的模拟分析,综合比较直吹式、浓淡分离式、横向扩张式和综合改造等进气结构,从而分析四种进气结构下的流场分布以及滤袋质量流量分配情况。结果表明:相对于直吹式的袋除尘器,采用浓淡分离进气和横向扩张进气的结构改进,袋室内部流场不均匀性降低,袋底磨损程度减弱。该研究的分析结果为袋式除尘器的改造和优化设计提供了理论依据。

There are some problems of non-uniform flow and wears of filter bags about bag-type dust collector of the boiler.In order to solve these problems,the structure of bag filter and airflow characteristic was improved and optimized.On the basis of flow field characteristics analysis about direct-blow air intake structure of bag type dust collector,respectively be reformed for rich-lean separation and lateral extension.Calculating fluid dynamics（CFD） software FLUENT is adopted to study the internal gas-solid two-phase flow field of bag filter.Internal flow field and the mass flow distribution under these four different air intake structures are given and compared.Results indicate that non-uniform flow field value and the wear of filter bags effectively can be reduced with these improvements of rich-lean separation and lateral extension,relative to direct blow air intake structure.The analyzed results of the research can offered the theoretical evidence for the improvement and optimizing design of bag filter.