摘要
针对锅炉受热面初始沉积层的热泳沉积机理建立了模型,采用文献中的实验结果及模型研究结果检验了模型的合理性,并通过考虑沉积层外表面温度随沉积层生长的动态变化改善了模型预测的准确性。结果表明:烟气温度和碱金属质量浓度高对热泳沉积表现为促进作用,烟气流速高对热泳沉积仅表现出微弱的促进作用;较高的管壁温度对热泳沉积表现为抑制作用;在相同的条件下,K2SO4的热泳沉积过程与Na2SO4具有高度的相似性,热泳沉积与气溶胶颗粒的组成成分无关;当气溶胶颗粒粒径小于1μm时,初始沉积层厚度与颗粒粒径的分布无关。
A model was established for the thermophoretic deposition based on thermophoresis mechanism of the initial deposition layer on the heating surface of a boiler,which was validated with the experimental and model results in relevant literature,while the prediction accuracy of the model was improved by considering the dynamic changes of surface temperature with the growth of the deposition layer.Results show that high flue gas temperature and high alkali metal concentration both promote the thermophoresis deposition,which is slightly influenced by flue gas flow.Meanwhile,high tube wall temperature inhibits the thermophoresis deposition.Under same conditions,the thermophoresis deposition process of K2SO4 has a high degree of similarity with that of Na2SO4,which is independent of the composition of aerosol particles.When the size of aerosol particles is less than 1μm,the thickness of initial deposition layer would be independent of the particle size distribution.
作者
孙恒清
盛昌栋
Sun Hengqing;Sheng Changdong(School of Energy and Environment, Southeast University, Nanjing 210096, China)
出处
《发电设备》
2020年第2期75-80,共6页
Power Equipment
基金
国家自然科学基金组织间合作研究NSFC-NSF项目(中美)(51661125011)。
关键词
生物质燃烧
热泳沉积
初始沉积层
biomass combustion
thermophoresis deposition
initial deposition layer
