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．HCl被选为Cl源加入流态化空气中，其含量在50～400 均间可调．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800 μm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 tocombined effect of corrosion and erosion. Some field studies have indicated a possible chlorine effect,where coals containing higher chlorine contents cause higher wastage rates. Tne effect, however, is neitherunderstood nor certain due to inoonclusive field and laboratory data. The purpose of this paper is to reportthe results of experiments using a wastage simulator to evaluate the effect of chlorine on in-bed tubewastage. Tbe rig was designed to simulate dense particle impacts on tube bottoms with well-controlledparameters, and has been proven to closely reflect situations found in operating bubbling FBVs. In thisstudy, HCl gas was chosen to be the chlcrine source and was introduced into the fluidized bed at 40～ 50μg/g concentrations. Tests were performed at temperatures ranging from ambient to 400℃ using 1018 lowcarbon steel rods in a bed of commercial SiO2 sand that had an average size of 800 μm. The wear profileafter each test was measured using profilometer. Results showed a significant increase in material wastagerates in the presence of HCl, and that the rate was greater with higher HCl concentrations. The magnitudeof the effect observed appears to be of the same order as that reported in practice.