一种SCR脱硝装置喷氨混合系统的结构优化设计

STRUCTURAL OPTIMIZATION OF A SCR DE-NOxUNIT WITH AMMONIA SPRAY MIXING SYSTEM

氮氧化合物是主要的大气污染物之一,已经成为我国大气污染控制的重点。SCR(selective catalytic reduction)烟气脱硝技术因其脱硝效率高、运行稳定而成为目前应用最为广泛的烟气脱硝技术。当前SCR烟气脱硝工程存在的主要问题之一是氨气的逃逸率过高,喷氨混合系统的混合强度和均匀度是影响氨气逃逸率的重要因素。针对该问题采用计算流体动力学的方法优化设计了一种SCR脱硝装置喷氨混合系统,采用该种喷氨混合系统可以有效提高氨气与烟气在催化剂表面的混合均匀度,使氨气与烟气中的氮氧化物在催化剂表面充分反应,有效降低氨气逃逸率,同时降低SCR脱硝工程成本。

Emission control of nitrogen oxides（ NOx）,one of the key air pollutants,becomes a hot topic of air pollution control in China. At present,SCR（ selective catalytic reduction） is the dominate technology used widely due to the high efficiency of de-NOxand stable operation. However,the considerable high ammonia slip is one of the main problems of the current SCR projects,resulting from the mixing intensity and uniformity of ammonia spray mixing system,usually. In this paper,the method of computational fluid dynamics（ CFD） is used to obtain an optimal design for a novel ammonia spray mixing system of a SCR de-NOxproject. The new ammonia spray mixing system can effectively improve the mixing intensity and uniformity of ammonia in the flue gas. With this new ammonia spray mixing system,ammonia can get reacted sufficiently with the nitrogen oxides in the flue gas over the catalyst,while the cost of SCR de-NOxproject is decreased.