Study On Changing Law Of The Char Surface Pore Structure In The Combustion Process

With the development of energy shortage and environment deterioration, people pay more and more attention to the study of coal utilization. The foundation of coal studies is the surface structure of char and the accurate description of its changing during char combustion. The effective token way in which the surface structure of char changes is that the distribution of surface aperture and the pore area ratio on the char surface, it has remarkable influence on gasification, liquefaction, combusted ratio of the coal. But in view of the complexity of the coal surface structure , and the restriction of the measured competence, mathematics descriptive method and computing capability in the past, people can only carry on apparent describing or qualitative analysis to the change of char surface during char combustion. The subject studies the distribution of surface aperture of char during char combustion.The main contents of this paper are as following:First, the char surface structure test technology and its current situation were summarized, including the understanding of char surface structure variations during combustion, and the test technology of surface structure. And discussing the description methods of char surface structure, the application of SEM and its current studying.Secondly, a certain study about distribution of surface aperture of char has been done, use the mightiness image process function of MATLAB software, combining Photoshop software ,make a MATLAB programme to deal with SEM image, and calculate the distribution of surface aperture. Analyzing to SEM images with this procedure, we can obtain the surface structure information of char, such as the quantity of pore area S expressed by dpi ,the scale of pore r, use a method to change the dpi into trim size, we can also obtain the relation of the quantity pore R and hole N. Calculate average big pore and middle pore and their quantities, make a foreshadowing for anther characteristic study about char surface structure .Finally, discuss the char surface variational law during char combustion. Mostly controlled by combustion temperature and combustion time, and the influence factors on the surface structure during char combustion, such as the radius of particle, coal, acid washing, etc., has been studied, then a series of experiment conclusions were drawn.