期刊首页 优先出版 当期阅读 过刊浏览 作者中心 关于期刊 English

《能源前沿(英文)》 >> 2021年 第15卷 第1期 doi: 10.1007/s11708-020-0806-9

Experimental studies of ash film fractions based on measurement of cenospheres geometry in pulverized coal combustion

State Key Laboratory of Multiphase Flow in Power Engineering, Department of Thermal Engineering, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China

录用日期: 2020-04-17 发布日期: 2020-04-17

下一篇 上一篇

摘要

In pulverized coal particle combustion, part of the ash forms the ash film and exerts an inhibitory influence on combustion by impeding the diffusion of oxygen to the encapsulated char core, while part of the ash diffuses toward the char core. Despite the considerable ash effects on combustion, the fraction of ash film still remains unclear. However, the research of the properties of cenospheres can be an appropriate choice for the fraction determination, being aware that the formation of cenospheres is based on the model of coal particles with the visco-plastic ash film and a solid core. The fraction of ash film is the ratio of the measuring mass of ash film and the total ash in coal particle. In this paper, the Huangling bituminous coal with different sizes was burnt in a drop-tube furnace at 1273, 1473, and 1673 K with air as oxidizer. A scanning electron microscope (SEM) and cross-section analysis have been used to study the geometry of the collected cenospheres and the effects of combustion parameters on the fraction of ash film. The results show that the ash film fraction increases with increasing temperature and carbon conversion ratio but decreases with larger sizes of coal particles. The high fraction of ash film provides a reasonable explanation for the extinction event at the late burnout stage. The varied values of ash film fractions under different conditions during the dynamic combustion process are necessary for further development of kinetic models.

相关研究