材料期刊网

采用实验室流态床燃烧器模拟装置评定氯化物对埋管耗损的影响.该模拟装置能重现埋管底部遭受密集颗粒的冲刷,其运行参数可控,以接近沸腾流态床所遇工况.HCI被选为Cl源加入流态化空气中,其含量在50-400μg/g间可调.试验温度范围由室温至400℃.以1018低碳钢棒代表埋管,床体为平均粒度800μm的工业用SiO2砂.结果表明,HCl明显地加剧材料的耗损，且其随HCl浓度的增加而加剧。本研究所获HCl加剧耗损程度的数量级与报道的现场结果相当。

Heat-exchanger tubes in fluidized bed combustors (FBCs) often suffer material loss due to combined effect of corrosion and erosion. Some field studies have indicated a possible chlorine effect,where coals containing higher chlorine contents cause higher wastage rates.Theeffect,however,is neither understood nor certain due to inconclusuve field and laboratory data. The purpose of this paper is to report the results of experiments using a wastage simulator to evaluate the effect of chlorine on in-bed tube wastage.The rig was designed to simulate dense particle impacts in tube bottoms with well-controlled parameters, and has been proven to closely reflect situations found in operating bubbling FBCs.In this study ,HCl gas wwas chosen to be the chloring source and was introduced into the fluidized bed at 40-50μg/g concentrations. Tests were performed at temperatures ranging from ambient to 400℃ using 1018low carbon steel rods in abed of commercial SiO2 sand that had an average size of 800μm .The wear profile after each test was measured using profilometer.Results showed a significant increase in material wastage rates in the presence of HCl, and that the rate was greater with higher HCl concentrations. The magnitude of the effect observed appears to be of the same order as that reported in practice.