燃煤电厂湿烟羽治理技术研究进展

Research progress on wet plume control technology in coal-fired power plants

湿法脱硫方式在我国燃煤电厂的脱硫系统中占主要地位,其中以石灰石-石膏湿法脱硫方式应用最多。湿法脱硫后的烟气通常为湿饱和烟气,若烟气在排放时环境的温度及湿度较低,则会在烟囱口产生"湿烟羽"现象。湿烟羽一般呈白色或灰色,含大量水汽及污染物,湿烟羽的出现对环境及人体健康产生危害。因此企业在采用脱白技术进行排放改造将会减少烟气中污染物的排放,使烟气更好地扩散。为了更好地了解湿烟羽现象,帮助待改造企业选用适合自身的技术路线,本工作对湿法脱硫工艺及湿烟羽形成原因进行了简单介绍,对国内部分地区出台的有关政策进行了汇总,并综述了湿烟羽特性的研究现状(包括湿烟羽的长度、抬升高度及消除特性)。湿烟羽的控制技术较多,主流技术可分为烟气冷凝技术、烟气加热技术及烟气冷凝再热技术,应用温湿图对各控制技术的原理进行解释,根据控制技术的分类对各类别下的应用进行了综述,提出控制技术复合使用的可能,在节能及经济性允许的前提下,各企业应尝试更多技术路线,为湿烟羽的治理拓宽道路。要点:(1)汇总了国内烟羽政策,综述了湿烟羽特性的研究现状。(2)重点综述了燃煤电厂湿烟羽控制技术的种类及应用,评论了各技术路线特点。(3)指出了湿烟羽控制技术研发方向,并给出了应用建议。

The wet desulfurization method plays a major role in the desulfurization system of coal-fired power plants in China,among which limestone-gypsum wet desulfurization is the most widely used.The flue gas after wet desulfurization is usually wet saturated flue gas.If the ambient temperature and humidity of the flue gas are low,it will produce a "wet plume" phenomenon at the chimney.Wet plumes generally appear white or gray,which contains a large amount of water vapor and pollutants.The emergence of wet plumes will be harmful to the environment and human health.Therefore,enterprises adopting plume elimination technology to carry out emission transformation will reduce the emission of pollutants in the flue gas,make the flue gas diffuse better.To better understand the phenomenon of wet plume and help the enterprises to be transformed to choose the technical route that suits them,this work first introduces the wet desulfurization process and the causes of the wet plume formation,followed by the relevant policies issued in some parts of China.The research status of wet plume characteristics(including the length,lift height and elimination characteristics of the wet plume) was summarized.There are many control technologies for wet plume.The mainstream technology can be divided into flue gas condensation technology,flue gas reheating technology and flue gas condensation and reheating technology.The article then applies the temperature and humidity diagram to explain the principle of each control technology,according to the classification of control technology.The applications under the category are reviewed.At the end of the work,the possibility of combined use of control technology is proposed.Under the premise of energy-saving and economical permission,enterprises should try more technical routes to broaden the road for the management of wet plumes.Key learning points:(1) The domestic policies about plume were summarized,and the research status of wet plume characteristics was reviewed.(2) The types and applications of wet plume control technology in coal-fired power plants were summarized,and the characteristics of each technical route were analyzed.(3) The research directions and applications of wet plume control technology were pointed out.