Study on the Changes of Pore Structure and Functional Group During Blended Coal Combustion
|School||Huazhong University of Science and Technology|
|Course||Thermal Power Engineering|
|Keywords||Blended coal TG Combustion characteristic Pore structure Functional group FTIR|
At present, most of power plants are actively or passively in use of the blended coals. In order to use the blended coals reasonably and effectively, economize the coal resource, increase the efficiency of boiler and maintain safely, effectively and economically operation of the power plant, it is necessary to systematically study on the changes of pore structure and functional group during blended coal combustion. It can also help us to understand the process of the blended coal combustion.First of all, the thesis used Thermogravimetric Analyser to analyse the combustion characteristics of the single and blended coals. The studies shown that the ignition temperature of blended coals doesn’t present a linear relationship with changes of the blend proportion. The ignition properties and comprehensive combustion characteristics of the blended coals were getting better with the proportion of Bituminous coal, but worse than the compositions’.Second, pore structure of coal char of different phases of single and mixed coal combustion was investigated by the determination of specific surface area and pore. From the analysis, it was shown that the single coals and blended coals had the same rule that the specific surface area increased rapidly and then gradually decreased during the coal combustion. And the contribution of micropore to the total specific surface area was the largest. The specific surface area had a greater impact on the combustion characteristics of the corresponding stage: the larger, the better of the combustion characteristics.At last, used the FTIR to analyse the changes of functional group during the coal combustion. From the analysis, we known that the blended coal was burning by stages. In combustion process of the blended, the start burning point of the flammable coal of the blended was comparatively delayed, but the difficult component was advanced, because of the ignition of the flammable one.