300MW燃煤电站化学团聚强化除尘协同脱硫废水零排放的研究

Research on Technology of Chemical Agglomeration Enhanced Fine Particles Removal and Zero Discharge of Desulfurization Wastewater From a 300MW Coal-fired Power Plant

提出一种新型化学团聚强化除尘协同脱硫废水零排放处理工艺。加入钝化团聚剂的脱硫废水喷入空预器前后烟道,分区梯级蒸发处理脱硫废水,强化细颗粒物脱除效率,实现细颗粒物和脱硫废水协同治理。实验室研究表明开发的钝化团聚剂可减缓脱硫废水中Cl离子的腐蚀性,缓蚀效率最高可达到74.83%。针对300MW燃煤机组,进行了化学团聚强化除尘协同脱硫废水零排放工业示范应用试验,综合考察了化学团聚强化除尘协同脱硫废水零排放系统对空预器、静电除尘器以及电厂运行参数的影响。试验结果表明,空预器后烟道喷入添加钝化团聚剂的脱硫废水2.5 m^(3)/h,满负荷条件下稳定运行,静电除尘器后粉尘浓度下降13.31%~32.19%,入口温度下降6.5℃左右,O2浓度增加0.08%。空预器前烟道喷入1.25 m^(3)/h脱硫废水,空预器出口温度降低在1℃之内,空预器压差没有增加。化学团聚强化除尘协同脱硫废水零排放系统长期连续运行,对电厂正常生产没有任何影响。

This paper proposed a new-type technology for the treatment of desulfurized wastewater,which uses enhanced chemical aggregation agents to improve the efficiency in removing the fine particles,and to attain the goal of zero-discharge in the treatment of desulphurized wastewater.Being mixed with passivated agglomerants,the desulphurized wastewater was sprayed into the flues that are installed at the inlet and the outlet of air preheater.The desulphurized wastewater flew through several sections of the flues,and was treated at different levels in different sections by the means of evaporation,which coordinated the control over the discharge of fine particles and desulfurized wastewater.As suggested by some experiments,the newly-developed passivated agglomerants can mitigate the corrosive effect of the Cl ions in the desulphurized wastewater.At the maximum,the corrosive effect can be reduced by 74.83%.In the case of a 300 MW coal-fired power unit,the exemplary experiment used the enhanced chemical aggregation agents to coordinate the control over the discharge of fine particles and desulfurized wastewater.A comprehensive investigation was conducted to find out the effects of the above-mentioned zero-discharge system on the air preheater,electrostatic precipitator,and the operation parameters of power plants.The desulphurized wastewater was sprayed at the speed of 2.5 m^(3)/h into the flue installed at the outlet of air preheater,and the zero-discharge system was working steadily at its full capacity.After the fine particles were treated by the electrostatic precipitator,concentration of fine particles dropped by 13.31%~32.19%.Compared with the temperature at the inlet of electrostatic precipitator,the temperature dropped by about 6.5℃.The concentration of O2 increased by 0.08%.The desulphurized wastewater was sprayed at the speed of 1.25 m^(3)/h into the flue installed at the inlet of air preheater.After the desulphurized wastewater was sprayed into the air preheater,the temperature of the outlet dropped by less than 1℃.There is no increase in the differential pressure.It is reveled in the experiment that the long-term operation of zero-discharge system does not have any negative effect on the normal operation of power plants.