燃煤电厂脱硫废水介稳区影响因素的实验研究

Experimental Study on the Influencing Factors of Metastable Zone of FGD Wastewater in Coal-fired Power Plants

燃煤电厂利用锅炉尾部烟气余热对脱硫废水进行喷雾蒸发处理技术应用前景广阔,但此技术存在烟道积灰等问题,研究脱硫废水介稳区的影响因素,对于评估该技术对烟道和除尘器等设备的影响十分关键。因此,本文采用激光法研究了脱硫废水的主要成分(MgCl_2-CaCl_2-NaCl复合盐溶液和单种盐溶液)在去离子水中的溶解度及超溶解度等热力学特性,以及金属离子、搅拌速率、pH值和飞灰对脱硫废水主要成分的介稳区的影响。研究发现金属离子的存在使脱硫废水介稳区变宽,是造成烟道积灰的主要因素,废水烟气混合紊流度、弱酸性环境和飞灰的存在将使脱硫废水介稳区变窄,促进废水晶体析出,可减少烟道积灰。

The treatment technology of spray-evaporating FGD wastewater using flue gas waste heat presents a wide application prospect, but this technology has some problems. To assess the effect of the Technology on the subsequent equipment, it is critical to study the influencing factors of metastable zone of FGD wastewater. With the laser monitoring observation technique, this study collected fun- damental thermodynamic measurement data regarding the solubility and supersolubility of the major components of FGD wastewater in the deionized water. Based on these data, this study discusses the influences of metal ions, stirring rate, pH and fly ash on the metastable zone of the major components of FGD wastewater. Specifically, this study finds that metal ions expands metastable zone, which is the primary cause of flue dust deposition, while the mixture turbulence intensity of waste water and gas. weak acid environment and fiv ash narrow metastable zone. which reduces the flue dust deposition.