SCR脱硝提效改造流场数值模拟及物模试验研究

Numerical Simulation and Physical Model Test of Flow Field for SCR Denitration and Efficiency Improvement

某燃煤电厂2×600MW机组脱硝装置运行过程中,出现催化剂磨损严重、氮氧化物(NOx)排放及氨逃逸量不达标等问题。为了解决这些问题,决定对流场进行优化。首先采用数值模拟方法,分析原方案流场存在的问题,提出合理的优化设计方案,再按照缩小比例进行物模试验验证,最后根据优化方案进行现场改造。优化改造后脱硝运行结果显示:NO_(x)排放浓度稳定在20—40mg/m^(3),氨逃逸量为1.2—2.0ppm,脱硝效率为86%—90%,达到了超低排放的要求。

During the operation of the denitration device of a 2×600MW unit in a coal-fired power plant,a series of problems occurred,such as serious catalyst attrition,excessive NOxemission and excessive amount of ammonia escape.In order to solve these problems,it was decided to optimize the flow field.First,the numerical simulation method was used to analyze the problems existing in the flow field of the original scheme,and a reasonable optimized design scheme was proposed.Then,the physical model test was verified according to the reduced scale.Finally,the on-site transformation was carried out according to the optimized scheme.After the optimization and transformation,the results of denitration operation showed that the NO_(x) emission concentration was stable at about 20-40mg/m^(3),the amount of ammonia escape was about 1.2-2.0ppm,and the denitration efficiency was about 86%-90%,which met the requirements of ultra-low emission.