生物质锅炉中碱金属氯化物迁移规律及对炉内结焦的影响

Study on the Migration of Alkali Metal Chloride and the Influence to Agglomeration in Biomass Boiler

生物质能是一种分布广、资源丰富的可再生能源。然而,这些生物质中碱金属元素含量普遍较高,在燃烧利用过程中碱金属容易与其它成灰元素(如氯、硅)发生化学反应,生成低熔点的物质而造成锅炉受热面结渣,影响锅炉运行的安全性和经济性。本文选用稻草秸秆作为研究对象,利用化学平衡软件Fact Sage中平衡模块EQUILIB对稻草秸秆燃烧过程进行热力学模拟。计算过程考虑了燃烧温度、炉内压力、过量空气系数、燃料中硫元素的含量和氯元素含量五个因素对碱金属氯化物迁移及锅炉结渣的影响,为工程应用中解决生物质锅炉结焦问题提供了参考。

Biomass energy is a kind of renewable energy. These fuels with high alkali contents, would react with other ash forming elements（such as Cl, Si）, form low-melt temperature materials and lead to ash sintering and slagging, which have affected the boiler operation safety and economy. In this paper, chemical equilibrium software Factsage is used to simulate the straw combustion process. The effects of combustion temperature, pressure, excess air coefficient, sulfur content and chlorine content on the migration of alkali metal chloride and the mechanism of agglomeration are considered. The results can provide guidance for solving the slagging during biomass combustion.