碱金属钠盐冷凝行为的实验研究

准东煤燃烧过程中,碱金属Na盐蒸气在锅炉对流受热面上的冷凝是形成积灰层的初始必要条件。利用一维沉降炉和冷凝采样器,对NaCl、Na2SO4及两者混合物的冷凝行为进行了实验研究。结果表明:NaCl、Na2SO4及两者混合物的冷凝温度分别为800℃、770℃和780~790℃。利用扫描电镜-X射线能谱(SEM-EDX)获得了不同温度区间冷凝产物的表面形貌及元素组成,分析并总结了2种冷凝机制:“异相凝结-部分熔融”和“均相成核-颗粒沉积”。

Condensation of sodium salt vapors on boiler convection surfaces is the initial and necessary condition for the formation of fouling layer during Zhundong coal is fired.In this paper,the condensing behaviors of sodium salt vapors(NaCl,Na2SO4 and their mixture)were studied by a one-dimensional furnace together with a novel condensation sampler.The results show that the condensation temperatures of NaCl,Na2SO4 and their mixture are 800℃,770℃and 780~790℃,respectively.SEM-EDX was applied to analyze the microstructure and elemental compositions of condensation products from different temperature ranges.In addition,the condensation mechanisms are discussed,heterogeneous condensation-partial melting and homogeneous nucleation-partial deposition.

作者李瑞宇龙纪淼李越胜曾向东喻孟全邓磊车得福LI Ruiyu;LONG Jimiao;LI Yuesheng;ZENG Xiangdong;YU Mengquan;DENG Lei;CHE Defu(Shunde Branch of Guangdong Institute of Special Equipment Inspection and Research, Shunde 528300, China;State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China;Guangdong Administration for Market Regulation, Guangzhou 510620, China)

机构地区广东省特种设备检测研究院顺德检测院西安交通大学动力工程多相流国家重点实验室广东省市场监督管理局

出处《锅炉技术》北大核心 2021年第1期9-13,共5页Boiler Technology

基金陕西省自然科学基金研究计划资助项目(2019JM-277)。

关键词碱金属准东煤冷凝 NACL NA2SO4alkali metals Zhundong coal condensation NaCl Na2SO4

分类号TK16 [动力工程及工程热物理—热能工程]