SCR喷氨管道及喷氨孔布置对流量均匀性的影响

Effect of SCR Ammonia Injection Pipes and Hole Layout on Flow Uniformity

针对一燃煤发电机组SCR脱硝装置喷氨管道和喷氨孔流量均匀性进行了分析。采用CFD方法获得了不同结构形式下喷氨管道及喷氨孔的流量分布。结果表明:喷氨管道不对称布置及喷氨支管沿单一方向开孔数过多会导致喷氨不均,喷氨管道和喷氨孔的流量差异较大;经针对性优化后,喷氨管道和喷氨孔流量均匀性显著提升,喷氨管道流量最大相对标准偏差从21.2%下降到3.4%;喷氨孔流量最大相对标准偏差从13.2%下降到7.4%;测试数据表明,优化后脱硝出口NO_(x)质量浓度分布均匀性显著提升,氨逃逸显著减少。

This paper analyzed the flow uniformity of ammonia injection pipes and holes in SCR denitration unit of a coal-fired generator unit.The flow distribution of ammonia injection pipes and holes under different structure was obtained by using CFD method.The results show that asymmetrical arrangement of ammonia injection pipes and too many holes of ammonia injection branch pipes in a single direction will lead to uneven ammonia injection,and the flow rate of ammonia injection pipes and holes has distant difference;after targeted optimization,the flow uniformity of pipe and ammonia injection hole was significantly improved,and the maximum relative standard deviation of ammonia injection pipe flow decreased from 21.2%to 3.4%;the maximum relative standard deviation of ammonia injection hole flow decreased from 13.2%to 7.4%;the test data showed that the distribution uniformity of the mass concentration of NO_(x) at denitrification outlet was significantly improved and the ammonia escape was significantly reduced after optimization.