摘要
目的针对锅炉燃烧高碱煤时存在的沾污问题,研究复合陶瓷涂层防高碱煤沾污性能。方法以水冷壁材料20G和过热器材料TP347为研究对象,采用料浆法在其表面制备复合陶瓷涂层,利用扫描电镜及能谱图观察分析实验后试样的微观形貌,对涂层的防Na_2SO_4、K_2SO_4、准东煤灰沾污性能进行研究。结果烧结固化后的复合陶瓷涂层表面致密,与基材结合状态良好。经过120 h的Na2SO4、K2SO4、准东煤灰沾污实验后,未喷涂涂层的20G及TP347钢片试样表面沾污率分别为20.31%、13.33%、32.31%和16%、10%、29%,而喷涂涂层的两种钢片试样表面沾污率分别为0.38%、0.26%、0.75%和0.26%、0.13%、0.39%,基本为零。未喷涂涂层钢片试样表面的片状氧化膜结构容易粘附一些细微的Na2SO4、K2SO4、准东煤灰颗粒,涂层表面的一些微裂纹也会使细微颗粒滞留在裂纹区域,这些细微颗粒难以被压缩空气吹扫清除。结论复合陶瓷涂层隔绝了沉积物与钢材基体直接接触,自身具有较低的表面能和化学不亲和性,使沉积物不易粘附,具有一定的防高碱煤沾污能力。
The work aims to solve fouling problem existing in boiler burning high-alkali coal by studying fouling resistance of composite ceramic coating to high-alkali coal. With water wall material 20 G and superheater material TP347 as study objects, composite ceramic coating was prepared on the surfaces in slurry method. SEM and EDS were used to observe and analyze microstructure of the samples after experiment, and study fouling resistance of the coating to Na2SO4, K2SO4 and Zhundong ash. The surface of composite ceramic coating was dense after sintering and curing, and was well bonded to the substrate. After 120 h fouling test of Na2SO4, K2SO4 and Zhundong ash, fouling rate of uncoated 20 G and TP347 steel sheet samples was 20.31%, 13.33%, 32.31% and 16%, 10%, 29%, respectively, and that of coated 20 G and TP347 steel sheet samples was 0.38%, 0.26%,0.75% and 0.26%, 0.13%, 0.39%, respectively, essentially 0%. Some subtle Na2 SO4, K2 SO4 and Zhundong coal ash particles might easily adhere to slice oxide film structure on the surface of uncoated sheet samples, some microcracks on the coating might also hold up fine particles in crack area. And the fine particles could hardly be removed by air blowing with compressed air. Composite ceramic coating prevented sediment from directly contacting with the steel substrate, exhibited lower surface energy and chemical incompatibility, thus the sediment was of low adhesivity and certain fouling resistance to high-alkali coal.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2017年第11期254-259,共6页
Surface Technology
基金
国家自然科学基金(51408574)
浙江省教育厅科研项目(Y201534242)
浙江省公益技术应用研究项目(2017C31043)
浙江省"仪器科学与技术"重中之重学科人才培育计划项目~~
关键词
燃煤锅炉
高碱煤
复合陶瓷涂层
料浆法
沾污
表面能
coal-fired boiler
high-alkali coal
composite ceramic coating
slurry method
fouling
surface energy
