脱硫废水浓缩液高温烟气直喷蒸发雾化研究及影响分析

Study and influence analysis of high temperature flue gas direct injection evaporation atomization of desulfurization wastewater concentrate

为实现燃煤机组脱硫废水不外排,主流的固化技术主要集中在利用锅炉尾部烟气热量进行消纳,但现有工艺技术均有一定的应用局限,为探索高效、低耗的新型废水消纳工艺方案,提出在不添加任何药剂的前提下,在空预器进口烟道直喷脱硫废水的消纳方案。空预器一侧直喷废水1 000 L/h,另一侧不喷射废水,通过两侧空预器对比试验研究空预器废水直喷对锅炉烟风系统的影响及可行性。结果表明,330 MW机组单侧空预器前直喷脱硫废水1 000 L/h,降低空预器进口烟气温度5.9℃,降低空预器出口烟气温度2.1℃,金属挂片变化、空预器差压、换热元件外貌形态、除尘器差压及滤袋性能指标与对比侧均无明显差异,且有利于飞灰几何粒径提升。研究结果表明脱硫废水空预器前消纳的工艺方案可行,高温段废水雾化效果较好,对锅炉烟风系统及后续主要设备不产生影响,废水消纳潜力巨大,具有较好的应用前景。

In order to realize the Zero discharge of desulfurization wastewater from coal-fired units,the mainstream solidification technology focuses on the absorption of heat from boiler flue gas,but the existing processes and technologies have certain application limitations.In order to explore a new type of wastewater absorption process with high efficiency and low consumption,it is proposed to directly inject desulfurization wastewater into the inlet flue of air preheater without adding any agent.Through the comparison test of air preheaters on both sides,1000 L/h waste water was directly injected on one side of the air preheater,and no waste water was injected on the other side.The influence and feasibility of direct injection of waste water from the air preheater on the boiler flue gas and air system were studied.The test results showed that there was no obvious difference in metal hanging pieces,differential pressure of air preheater,appearance and shape of heat exchange elements,differential pressure of dust collector and performance index of filter bag.It was beneficial to improve the geometric particle size of fly ash.The research results showed that the process scheme of desulfurization wastewater before air preheater was feasible,the atomization effect of wastewater in high-temperature section was good,the boiler flue gas and air system and subsequent main equipment were not affected,and the potential of wastewater consumption was huge,which had a good application prospect.