燃煤电厂SCR脱硝系统数值模拟研究进展

我国现役燃煤电厂完成超低排放改造后部分出现NO_x排放不达标的现象,为解决燃煤电厂该工程实际难题,对燃煤电厂SCR脱硝系统数值模拟研究现状进行了综述并开展了横向对比研究。结果表明:为进一步提高SCR脱硝系统数值模拟精确度,应采用非均匀的烟气入口边界条件和采用考虑基于灰层抑制的焦炭燃烧模型;导流板改造应加入对导流板厚度与烟道内烟气流动特性关系之间的考虑;喷氨系统及混合器改造是导致改造成本及引风机能耗较高的重要原因,对工程改造与改造后能耗增加的成本和节省催化剂成本间的对比研究是未来研究的热点。基于上述结论,提出了燃煤电厂SCR脱硝系统工程改造的技术路线,以期为工程实际提供理论指导及技术支撑。

RESEARCH PROGRESS ON NUMERICAL SIMULATION OF SCR DENITRIFICATION SYSTEM IN A COAL-FIRED POWER PLANT

After the ultra-low emission transformation of China's active coal-fired power plants, the NO_x emission of some of them doesn't meet the standard. In order to solve the practical problems of the projects in coal-fired power plants, we summarized the research status of numerical simulation of SCR denitration system in coal-fired power plants. The research shows that in order to further improve the accuracy of numerical simulation of SCR denitration system, non-uniform flue gas inlet boundary conditions and coke combustion model based on ash layer suppression should be adopted; the relationship between the thickness of the deflector and the flue gas flow characteristics in the flue should be considered in the reconstruction of the deflector; the transformation of the ammonia injection system and mixer is an important reason for the high transformation cost and induced draft fan energy consumption. The comparative study between the engineering transformation and the increased cost of energy consumption after the transformation and the cost saved on catalyst will be a hot research direction in the future. The technical route for the engineering transformation of SCR denitration system in coal-fired power plants is proposed, which can provide theoretical guidance and technical support for the engineering practice.