单塔双循环高效脱硫技术在超低排放节能改造中多被采用,然而部分采用单塔双循环脱硫系统的燃煤电厂出现集液盘下方最高喷淋层结垢严重的现象,喷淋层也有较多喷嘴与支管发生堵塞.以A、B两电厂为例,通过对现场设备与系统的检查,垢样及堵塞物实验室成分分析,以及脱硫塔流场分布数值模拟,分析认为上述问题与集液盘尺寸、附近流场分布、浆液池容积、浆液pH值控制等因素有关.为解决集液盘下方最高喷淋层结垢严重的问题,应从脱硫系统设计入手,加强运行参数控制.B电厂将集液盘下方最高层喷淋层喷嘴换为双向喷嘴,同时加强了运行过程中的补浆调整及相关参数控制,使问题得以解决.%Single tower with dual loop desulfurization system has been widely used in the retrofit of ultra-low emission. However, severe scale problem has taken place in the top slurry spray layer under the slurry collecting bowl in some coal-fired power plants with some nozzle and branch pipe of slurry spray layer also blocked. In this paper, two coal-fired power plants denoted by A and B are taken as examples. Through the examination of the on-site equipment and system, the analysis on the composition of scale sample in laboratory, and the numerical simulation on the flow field distribution of the desulfurization tower using CFD software, it is concluded that the scale problems are related to the size of slurry collecting bowl, nearby flow distribution, the volume of the slurry tank and pH of the slurry. In order to avoid the scale problem, starting from desulfurization tower design, operation parameters control and equipment maintenance should be enforced strictly. In power plant B, the one-way nozzles of the top slurry spray layer under the slurry collecting bowl had been replaced with two-way nozzles and the operation parameters have been also improved. Eventually, the scale problem of power plant B was solved successfully.
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