文献类型：期刊文献

英文题名：Investigation of fluctuation behavior in viscosity of coal slags used in entrained-flow gasifiers

作者：Ma, Yashi[1];Wu, Guixuan[3];Guo, Qinghua[1];Liu, Xia[1];Gong, Yan[1];Yu, Guangsuo[1,2]

机构：[1]East China Univ Sci & Technol, Minist Educ, Key Lab Coal Gasificat & Energy Chem Engn, Shanghai 200237, Peoples R China;[2]Ningxia Univ, Coll Chem & Chem Engn, State Key Lab High Efficiency Coal Utilizat & Gre, Yinchuan 750021, Peoples R China;[3]Forschungszentrum Julich, Inst Energy & Climate Res, Microstruct & Properties Mat IEK 2, D-52425 Julich, Germany

年份：2018

卷号：181

起止页码：132

外文期刊名：FUEL PROCESSING TECHNOLOGY

收录：;EI(收录号：20183905875673);WOS:【SCI-EXPANDED(收录号:WOS:000449900500013)】；

基金：This work was supported by National Key R&D Program of China (2017YFB0602601) and National Natural Science Foundation of China (21676091).

语种：英文

外文关键词：Coal slag; Gasification; Viscosity; Crystallization; Bubbles

摘要：Entrained-flow gasification has attracted extensive attention because of its clean and efficient utilization of coal as well as flexible application in industry for power generation and chemical production. Numerous theoretical and experimental investigations on slag flow in entrained-flow gasifiers have been performed to ensure a smooth operation, but an unscheduled shutdown due to slag tap blockage remains an ongoing challenge. A fluctuation phenomenon of slag viscosity gives a rise in the risk of slag tap blockage. In this work, three Chinese coal slags with low silicon content and high iron content were used to investigate the viscosity fluctuation phenomenon. It was found that the crystalline phases and suspended bubbles can cause the fluctuation phenomenon. The fluctuation degree is related to the volume fraction of crystalline phases and the crystallization rate. In the search for the mechanism of the viscosity fluctuation, an in-situ observation using a high temperature stage microscope system (HTSM) in combination with XRD and SEM analyses was carried out. In addition, the viscosity of investigated slags with the suppression of solid phases as well as the phase distribution at high temperatures was calculated. Based on a comprehensive analysis of the results, a possible mechanism has been proposed that the viscosity fluctuation is attributed to an instant local change in the macrostructure such as the deformation of suspended bubbles, the change of the orientation of acicular crystals and the interaction of the acicular crystals and suspended bubbles.