Biomass fly-ash deposition: Dependence of deposition rate on probe/particle temperature in 115-1200 °C range

FUEL

卷:290

Article

Weber, Roman¹  Poyraz, Yunus¹  Mancini, Marco¹  Schwabauer, Andreas¹ 

[1] Tech Univ Clausthal, Inst Energy Proc Engn & Fuel Technol, D-38678 Clausthal Zellerfeld, Germany

关键词: Biomass combustion;    Ash deposition;    Pilot-scale and industrial-scale data;   

DOI  :  10.1016/j.fuel.2020.120033

来源: Elsevier

【 摘 要 】

Seven biomass fuels were fired to determine the relationship between the ash deposition rate and the probe/ash-particle temperature varied in the 115-1200 degrees C range. The experiments were carried out at deposition-probe Reynolds number in the 40-60 range and Stokes number in the 0.8-1.9 range. The relationship between the deposition rate and probe/ash-particle temperature was determined to have a U-shape with the largest rates occurring at the largest (in excess of 1100 degrees C) and the lowest (115 degrees C) temperatures. When both the flue-gas and probe temperatures were in excess of 1100 degrees C, inertial impaction was the mechanisms of deposit build up; a correlation between the sticking propensity and (K + Na + Ca)/(Si + Al + Fe) ratio was observed. Thermophoresis was identified as the primary mechanism of deposit build up at 600 degrees C probe temperatures and 978 degrees C flue-gas temperature. At probe temperatures around 115 degrees C, condensation of Potassium salts was substantial, and so was thermophoresis both forming a sticky layer on the deposition surface. Thus, condensation, inertia impaction and thermophoresis have contributed to the deposit build-up at 115 degrees C probe temperature although in different proportions depending on the fuel combusted.

【 授权许可】

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