燃气电厂卧式余热锅炉SCR烟气脱硝喷氨设计优化

Optimal Design of Ammonia Injection Grids for Flue Gas SCR-De-NO_x Facility of Horizontal Heat Recovery Steam Generator

以燃气-蒸汽联合循环电厂卧式余热锅炉(HRSG)的SCR烟气脱硝装置为对象,基于计算流体力学仿真(CFD)技术,研究了超短距喷氨均匀度调控问题。在燃气电厂余热锅炉脱硝装置中,SCR装置的特殊性在于超短的氨/烟气混合距离。喷氨格栅与催化剂反应面之间只有4m距离,要在如此短距离内实现氨浓度均匀分布的要求是非常困难的。通过利用CFD仿真模拟技术,优化喷氨格栅的结构参数,优化喷氨嘴配置,达到了很好的氨/烟气混合效果,使氨浓度相对标准差小于3%。

In this paper, optimal structure design for selective catalytic reduction （SCR） of nitrogen oxides in the flue gas for a horizontal Heat Recovery Steam Generator （HRSG） is carried out. The SCR De-NOx facility is characterized with extremely limited ammonia/NOx mixing space. The distance between the ammonia injection grid and the catalyst is as short as 4m, and therefore, regulation of the ammonia concentration distribution becomes a very chal- lenging task. The regulation is carried out via optimizing the structural parameters of the am- monia injection grids, Optimal configuration of the ammonia injection nozzles is achieved based on computational fluid dynamics simulations, which results the standard variation of the ammonia concentration distribution of less than 3%.