选用高钙、高铁神华煤,在高温沉降炉中进行空气及富氧燃烧条件下的煤灰沉积实验,利用x射线荧光探针(XRF)、扫描电镜(SEM)及能谱仪(EDS)对灰渣的化学成分和微观形貌进行深入表征,研究了燃烧气氛和氧气浓度对神华煤灰沉积特性的影响。结果表明,在所研究的实验条件下,燃烧气氛和氧气浓度对神华煤灰沉积特性具有很大影响。与空气燃烧相比,相同氧浓度富氧燃烧中灰沉积更严重。富氧燃烧条件下,灰沉积倾向随氧气浓度的升高而降低,灰渣结构更致密。燃烧工况对灰渣中主要元素种类没有显著影响,但影响它们的相对含量。
Ash deposition tests with Shenhua coal, which has high contents of Ca and Fe, were carried out on a drop tube furnace under air and oxy-fuel combustion conditions. XRF, SEM and EDS were used to characterize the chemical composition and micro-morphology of the slag. The influence of combustion atmosphere and oxygen concentration on ash deposition was investigated. The results showed that combustion atmosphere and oxygen concentration had significant influences on Shenhua coal ash deposition. Ash deposition was more severe in oxy-coal combustion at the same oxygen concentration when compared to the air case. For oxy-coal combustion cases, as the oxygen concentration increased, ash deposition decreased and the slag became denser. Changing combustion conditions did not affect the elements in the slag but affect their relative proportions.