生物质在锅炉中燃烧时,碱金属蒸气在高温对流受热面上的凝结是形成积灰层的初始必要条件。本文利用一维沉降炉和凝结采样器,对KCl、K_2SO_4及两者混合物的凝结特性进行了实验研究。结果表明KCl、K_2SO_4及两者混合物的凝结温度分别为770、745和764℃左右。利用扫描电镜对不同温度范围的凝结产物表面形貌进行了分析,得到了两种凝结机制:“异相凝结-部分熔融’和”均相成核颗粒沉积"。 When the biomass burns in the boiler, the condensation of alkali metal vapor on the high temperature convection heating surface is the initial requirement for the formation of the ash layer. In this paper, the coagulation characteristics of KCl, K_2SO_4 and their mixtures were experimentally studied by one-dimensional settling furnace and condensation sampler. The results show that the condensation temperatures of KCl, K 2 SO 4 and their mixtures are about 770, 745 and 764 ℃, respectively. Scanning electron microscopy (TEM) was used to analyze the surface morphology of the coagulated products in different temperature ranges. Two coagulation mechanisms were obtained: heterogeneous coagulation-partial melting and homogeneous-nucleation granular deposition.