摘要
余热锅炉积灰对其传热特性具有很大影响。分析了余热锅炉的积灰特性、积灰成因和积灰区域的特性,并结合积灰导热系数等物性参数,采用湍流流动标准k-ε模型,定性地分析积灰对光管传热特性的影响。研究表明,随着烟气流速的增大,积灰后的光管Nu数都增大,且积灰后光管的Nu数小于未积灰时的Nu数;积灰后光管Nu数的减小比例随着烟气流速的增大而减小;积灰后烟气进出口压力差变化较小,对换热段烟风阻力影响较小。
Ash deposition in the waste heat boiler presents major impact on its heat transfer performance. The characteristics and causes of ash deposition in the waste heat boiler and the characteristics of the ash deposition areas are examined. Based on the parameters such as the ash deposition heat transfer coefficient,turbulent flow standard k-ε model is used to quantitatively analyze the impact by the ash deposition on the heat transfer performance of the bare tubes. The study shows,as the flue gas flowrate increases,the Nu numbers of the bare tubes after ash deposition all increase,and the Nu numbers of the bare tubes after ash deposition are smaller than the Nu numbers without ash deposition; the decrease ratio of Nu numbers of bare tubes after ash deposition decreases as the flue gas flowrate increases; after ash deposition,the differential pressure variance between the flue gas inlet and outlet is small,and the impact on the flue gas resistance of the heat exchange section is small.
引文
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