1000MW机组脱硝系统流场模拟与优化

Simulation and Optimization of Flow Field of 1000 MW Unit DeNO_x System

脱硝装置中流场分布不均会严重影响脱硝效率及催化剂使用寿命。针对超超临界1 000 MW机组配套脱硝系统实际应用案例较少,经验不足等问题,以1 000 MW机组配套脱硝装置为仿真对象,通过改直角弯道为圆角弯道,在不同位置增设不同尺寸、形状的导流板,催化剂上方增设整流格栅对其内部流场进行优化,并通过云图及均方根值进行定性及定量分析。研究表明:导流板及整流格栅可以改变烟气流动的方向,对烟气进行深度整流,使烟道及催化剂上方截面速度分布偏差系数降低到15%以下。在SCR反应器及烟道内合理增设导流及整流装置,可以使流场分布趋于均匀,提高脱硝反应效率和催化剂使用寿命。

The uneven flow field distribution of denitration device will seriously affect the denitration efficiency and service life of catalyst. In the light of the fact that the 1 000 MW ultra-super critical units supporting denitrification systems lack practical cases and experiences,by changing right-angle corners into rounded ones,adding baffle of different size and shape in different position,and adding rectification grid above catalyst to optimize its internal flow field,the 1 000 MW units supporting denitration system is set up as a simulation object via qualitative and quantitative analysis through contours and RMS Results of the research show that the deflector and rectifier grille can change the direction of flue gas,so by rectifying the gas flow deeply the Cv value of flue and the section above catalyst can be reduced to 15% or even less. Appropriate arrangement of deflector and rectification grid in denitrification reactor and flue can improve the uniformity of the flow distribution and denitration reaction efficiency and catalyst life as well.