排烟余热利用技术分析.docxVIP

摘 要锅炉排烟热损失一直都是锅炉热损失中最主要的一项。排烟温度偏高一直是国??内各个电站普遍存在的问题,尤其是运行了一段时期的电站,因为运行参数偏离了??设计参数,或煤种变等原因,常常造成排烟温度过高。这不仅影响电厂的热经济??性,而且为烟气换热器的安全运行也埋下隐患。因此,为了提高电站运行的安全可??靠性且做到节能降耗,必须想办法降低排烟温度。余热回收是一项国家鼓励与大力扶持、推广的节能环保项目。“十一五”期间,国家对余热再利用产业实施的专项扶持政策,有力地促进了我国余热回收技术进步和产业发展。“十二五”对余热再利用产业扶持政策力度的加大,其市场前景会更加广阔。中低温烟气一般含有腐蚀性物质、飞灰等杂质,而且烟气温度相对较低,热品质低,直接影响了烟气余热利用方案的实施或正常运行。文中首先介绍了烟气余热利用过程中低温腐蚀、积灰的产生机理以及各自的影响因素,然后提出了防止低温腐蚀及积灰的措施,对于中低温烟气余热利用装置的设计与运行起到参考作用。分别用热平衡法、火用平衡法、能级平衡法对余热利用装置进行热经济经分析及评价,得出余热利用的基本原则,不仅要从量上充分利用余热而且要从质上充分利用余热,要做到按质用能、梯级利用。本文介绍了降低排烟温度和排烟损失的各种途径,并重点介绍了烟气换热器系统在降低排烟温度上的实际应用情况。??本文研究了烟气换热器系统的工作原理,分析了影响经济性的各个参数,给出??了优化设计模型。并以某电站加装低压省煤器为例,在给定排烟温度的条件下,依??据优化设计模型,计算得到了换热器最优受热面布置方式。然后依据局部经济性计算的方法对加装烟气换热器的热力系统进行了分??析,为烟气换热器的优化选型提供参考。关键词：排烟; 余热利用; 热力分析; 换热器；优化设计AbstractBoiler exhaust heat boiler heat loss is always the most important one loss. High exhaust gas temperature of each power plant has long been a common problem, especially in a period of running the station, because the operating parameters deviate from the design parameters, or change coal and other reasons, often resulting in the exhaust gas temperature is too high. This not only affects the economy of thermal power plants, but also for the safe operation of the flue gas heat exchanger also lay hidden. Therefore, in order to improve the safety and reliability of plant operation and to achieve energy saving, we must find ways to reduce exhaust gas temperature. Heat recovery is a country to encourage and strongly support the promotion of energy saving projects. During the Eleventh Five-Year, the state of implementation of waste heat recycling industry special support policies, effectively promoted the development of Chinas progress and industrial waste heat recovery technology. Twelve Five for waste heat re-use industrial policy efforts to increase its market prospects will be even brighter. Average low temperature flue gas containing corrosive substances, fly ash and other impurities, and relatively low flue gas temperature, low