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通过差热天平、粒度分析、红外光谱等方法对微波处理前后的煤粉进行了试验分析。结果表明,改质煤粉在不同升温速率下的燃烧性能都明显增强;微波辐射使煤粉粒度降低,但由于幅度较小而未对煤粉中碳基质的燃烧性能产生明显影响,说明微波辐射并未对煤中碳基质的燃烧性产生作用;微波辐射使煤粉中高活性官能团数量明显增加,说明煤粉燃烧性能的提高是挥发分活性提高的结果;利用Flynn-Wall-Ozawa(FWO)非等温模型对煤粉燃烧过程的动力学分析发现,当转化率低于50%时,微波辐射煤粉的活化能低于原煤。云岗和阳泉煤粉经过微波辐射处理后,20%转化率时的活化能分别降低20.37和26.91J/mol。随着转化率的增加,原煤和改质煤粉的活化能差距减小,云岗和阳泉改质煤粉的活化能分别在50%和60%的转化率时与原煤达到同一水平。超过这一转化率以后,改质煤粉活化能小幅高于原煤,但基本与原煤保持在同一水平。
Through the differential thermal balance, particle size analysis, infrared spectroscopy and other methods of microwave treatment before and after the pulverized coal were analyzed. The results showed that the combustion performance of modified pulverized coal increased obviously under different heating rates. The microwave radiation reduced the particle size of pulverized coal, but the smaller the pulverized coal did not affect the combustion performance of carbonaceous coal. The effect of microwave irradiation on the activity of volatiles increased with the increase of the combustion activity of coal, which did not affect the combustibility of carbon matrix in coal. The number of highly active functional groups in coal increased significantly with microwave irradiation. The kinetic analysis of the coal combustion process shows that the activation energy of microwave radiation coal powder is lower than that of the raw coal when the conversion rate is less than 50%. After microwave radiation treatment, the activation energy at 20% conversion of Yungang and Yangquan pulverized coal decreased by 20.37 and 26.91 J / mol, respectively. As the conversion rate increases, the difference between the activation energies of raw coal and upgraded coal decreases, and the activation energies of the upgraded coal of Yungang and Yangquan reach the same level with the raw coal at the conversion rates of 50% and 60% respectively. After this conversion rate, the activation energy of modified coal is slightly higher than that of raw coal, but the basic coal maintains the same level with raw coal.