660MW机组SCR脱硝板式催化剂磨损分析

660MW Unit Denitrification SCR Plate Catalyst Wear Analysis

针对马鞍山当涂电厂660MW机组脱硝SCR(选择性催化还原)板式催化剂发生局部严重磨损的现象,文章依据多次实际测量的数据进行对比分析,发现磨损呈现规律性分布,并且与脱硝反应器内部结构相关联。通过冷态流场计算及灰场数值计算分析研究表明:催化剂局部严重磨损的主要原因是由于反应器的顶部梁结构布局不合理,造成烟气流量、流速分布不均,引起催化剂局部出现严重磨损。针对这一原因,文章提出通过移除脱硝反应器上方的积灰三角以及改变喷氨烟道上方导流板的直径和角度等措施来改善脱硝反应器中烟气的流速分布。数值模拟的计算结果表明,在相同的运行工况下,改善后的脱硝反应器中烟气流速的均匀性得到了显著的提高,有效抑制了催化剂局部出现严重磨损等不良现象的发生。

According to the local serious wear and tear occurred on a 660MW unit in a power plant deni-trification SCR （ selective catalytic reduction） plate catalyst, this paper collects the actual measurement data, and after comparing and analyzing many times, it is found that the wear issue is showed in regular distribution, and is associated with denitrification reactor in internal structure.Through the cold flow field calculation and ash field numerical analysis, the research shows that the main reason for partial severe wear of catalyst is because of the unreasonable top beam structure layout of reactor.Due to this reason, the flue gas flow is concentrated on front beam contributing to the quantity of flow concentrated and above the catalyst module the uneven gas velocity.Therefore, the local severe wear is caused in catalyst.For this reason, this article puts forward a plan to improve the velocity distribution of the flue gas in denitrifi-cation reactor by removing the triangle deposition on the top of the denitrification reactor and changing the diameter and angle of the guide plate on the top of spraying ammonia flu.Numerical simulation results show that under the same operating conditions, the uniformity of flow velocity in the flue gas denitrifica-tion reactor is significantly improved, and the catalyst local severe wear as well as other adverse reactions is effectively inhibited.