准东煤飞灰沉积特性及数值模拟研究  

Sedimentation Characteristics and Numerical Simulation of Zhundong Coal Fly Ash

作　　者：滕晓龙 胡丽娜 张文超 李高超 Teng Xiaolong;Hu Lina;Zhang Wenchao;Li Gaochao(School of Electrical Engineering,Xinjiang University,Urumqi 830046,China)

机构地区：[1]新疆大学电气工程学院,乌鲁木齐830046

出　　处：《燃烧科学与技术》2024年第4期419-428,共10页Journal of Combustion Science and Technology

基　　金：新疆维吾尔自治区重大专项资助项目(2022A01002-2)。

摘　　要：针对燃用准东煤锅炉出现的积灰结渣现象,研究了准东煤在不同灰化温度下灰颗粒元素含量变化,建立灰沉积模型,对灰颗粒在圆管壁面的沉积特性进行数值模拟.结果表明:烟气温度600℃时,灰颗粒表面无明显熔融现象,且EDS结果中Si、Al元素含量高,计算黏度值远高于临界黏度,随着烟气流速提高,反弹的灰颗粒粒径减小,积灰扩展角减小;随着烟气温度升高,烟气温度800℃时的最大积灰厚度为烟气温度600℃时最大积灰厚度的近3倍,灰化温度达到800℃时灰颗粒表面出现黏结现象,灰颗粒的黏附能力增强;烟气温度达到900℃时,积灰厚度进一步提高,结合实验结果可知,微米级灰颗粒表面出现明显熔融现象,且EDS结果显示Fe元素含量高达28%,计算黏度值接近临界黏度.Aiming at the ash accumulation and slagging in boilers burning Zhundong coal,the changes of ele-mental content of ash particles after the ashing of Zhundong coal at different temperatures were studied,an ash deposition model established,and the deposition characteristics of ash particles on the wall of the round tube simu-lated numerically.The results show that when the flue gas temperature is 600℃,the surface of ash particles is rough,the Si and Al elements in the EDS results are high in content,and the calculated viscosity is much higher than the critical one.As the flue gas flow rate rises,the extension angle of ash accumulation is reduced with the decreasing size of rebounded ash particles.The maximum thickness of the ash accumulated at the flue gas tempera-ture of 800 is nearly three times that at 600.When the a℃℃shing temperature reaches 800℃,it can be seen that a bonding occurs on the surface of the ash particles,whose adhesion ability is then enhanced.When the flue gas temperature reaches about 900℃,the thickness of the accumulated ash is further increased.An obvious fusion occurs on the surface of the micrometer-sized ash particles,the content of Fe element is as high as 28%,as indi-cated by the EDS results,and the calculated viscosity is close to the critical one.

关 键 词：准东煤 灰化温度 黏度 烟气温度 烟气流速 

分 类 号：TK16[动力工程及工程热物理—热能工程]