内置导流板的湿法脱硫塔数值模拟优化及应用

Numerical Simulation Optimization and Application of Wet Desulfurization Tower with Inner Guide Plate

针对传统湿法脱硫系统普遍存在的脱硫效率不高、阻力损失过大的问题,提出了一种基于导流板的塔内烟气流场优化与增效降阻改造方案。采用数值模拟方法研究了各导流板方案对塔内流场分布及流动阻力特性的影响,确定了最佳导流板布置方案,并应用该方案对某电厂600MW机组脱硫塔进行改造。结果表明:与改造前相比,改造后塔内烟气流场的均匀性得到显著提升,脱硫塔在距托盘上方1.5m处的速度相对标准偏差由52.5%降为18.7%;脱硫塔在主要运行负荷段(300~480MW)出口烟气SO2质量浓度可降低约10mg/m3;改造后脱硫塔在满足超低排放的前提下,投入3台浆液循环泵运行时的负荷临界点由390~410MW提升至430~450MW;当改造前后一定负荷范围内运行同样数量的浆液循环泵时,改造后脱硫塔进出口流动阻力比改造前降低了约100Pa。

According to the problem of ubiquitous low desulfurization efficiency and excessive resistance loss in traditional wet desulfurization system,a retrofit scheme of flow field optimization,efficiency enhancement and resistance reduction was proposed based on guide-plate.Numerical simulation method was used to study the effects of guide plate schemes on flow field distribution and flow resistance characteristics in desulfurization tower.The optimal arrangement was determined and then applied in the retrofit of desulfurization tower in a 600MW boiler of power plant.Results show that the uniformity of flue gas in tower can be improved obviously after retrofit.The relative standard deviation of flow velocity above 1.5mof tray can be decreased from 52.5%to 18.7%.At the main operation load range(300-480MW),the SO2 concentration of flue gas at outlet can be reduced by about 10mg/m3.The critical operation load can be improved from 390-410MW to 430-450MW in the condition of three slurry circulation pumps running.The flow resistance can be reduced by about 100Pa than before in the same circulation pump operation parameters within a certain load range.