W火焰锅炉SNCR烟气脱硝工艺优化

Optimization design of SNCR process for W-flame boiler

为优化某600 MW机组W火焰锅炉选择性非催化还原(SNCR)烟气脱硝工艺设计,本文通过化学动力学分析和流体动力学分析,对其脱硝系统进行模拟,确定了研究对象采用SNCR烟气脱硝工艺的温度、理论脱硝效率、喷枪布置位置等设计参数,最终获得46%的实际脱硝效率。分析结果表明:化学动力学分析未考虑还原剂与NO_x混合不均匀带来的影响,获得的理论脱硝效率较高;流体动力学分析考虑了传质的影响,得到的脱硝效率低于理论值;说明实际工程中,混合传质是影响SNCR脱硝效率的重要因素。

To optimize the design of selective non-catalytic reduction （SNCR） process for a 600 MW W-flame boiler, the chemical kinetics analysis and fluid dynamics analysis were applied to simulate the SNCR process. The design parameters of the SNCR process including the design temperature, de-nitrification efficiency in theory and position of spray gun were determined, and a denitrification rate of 46% was finally obtained. The results show that, the chemical kinetics analysis deosn＇t consider the effect of nonuniform mixing of the reducing agent and NOx, so the theoretical efficiency is higher. The fluid dynamics analysis takes into account the effect of mass transfer, so the de- nitrification efficiency is lower than the theoretical value. In practical engineering, the mixed mass transfer is an important factor affecting the efficiency of SNCR denitration