不同入口浓度时湿法脱硫塔运行参数优化的数值研究

Operating Optimization of a Desulfurizing Tower at Different Initial Sulfur Dioxide Concentrations

采用计算流体力学技术,对一台220t/h循环流化床锅炉配置的湿法脱硫塔进行了数值模拟,主要研究了不同入口SO2浓度时脱硫塔的优化运行策略。模拟结果表明,脱硫塔压降为700Pa,塔内速度与温度分布均匀,入口SO2浓度为2000mg/Nm^3时,净化后降低为32mg/Nm^3,与实际运行情况吻合。当脱硫塔入口SO2浓度降低至1000mg/Nm^3,为了满足35mg/Nm^3排放指标,可投用第1和第3层,或第1和第2层,并将每层喷淋量增加20%。当入口SO2浓度增加至3000mg/Nm^3,较优的运行方案是投用4层喷淋层,并将液气比增加至25.6L/Nm^3,可以达到超低排放要求。

Based on computational fluid dynamics technology,a wet desulfurizer of a 220 t/h circulating fluidized bed boiler is numerical simulated to investigate the optimal operating modes at varied initial concentrations of sulfur dioxide.The results show that the pressure drop of the desulfurizer is 700 Pa,and the flow distribution of flue gas is good.The SO2 concentration is simulated to be 32 mg/Nm 3 at an initial value of 2000 mg/Nm^3,which agrees with the actual value.At an initial SO2 concentration of 1000 mg/Nm^3,the optimal operating mode is using both the first and the third levels of sprayers,or using the first and the second levels of sprayers.Meanwhile,the flow rate of desulfurization liquid of every level should be increased as 20%to meet the ultra-low-emission index.At a high initial SO2concentration of 3000 mg/Nm^3,the optimal operating mode is using all the four levels of sprayers,and raising the liquid-gas ratio to 25.6 L/Nm^3.