单颗粒煤孔隙结构的数值模拟研究-动力工程专业论文.docxVIP

内蒙 内蒙古科技大学硕士学位论文 内蒙 内蒙古科技大学硕士学位论文 PAGE PAGE IV PAGE PAGE III Abstract Coal is an important part of nature, and useful for our daily lives. It is porous and has many tiny pores inside the coal particles. First of all, test methods and different theoretical models were summarized for pore structure of coal particles, and advantages and disadvantages of the methods and its scope of application types were analyzed. Next, the resolution of various test methods, measurement range, work environment, temperature and damages to samples were summed up. Then microscopic pore structure of coal was analyzed by electron microscopy and reconstructed numerically with Monte Carlo method. Main contents and conclusions are as follows: Firstly, industry analysis of B1 ~ B3 coal samples determined B1 as anthracite, B2 as lignite, B3 as bituminous coal. Scanning electron microscope analysis found that the pore size, pore shape and pore distribution varied from different kinds of coal. Anthracite has larger pore size and number, and the pores are close together; Lignite coal mainly has medium and small pores; Bituminous’ pore shapes are different and small number of them belong to structural fracture. And pores of bituminous are evenly distributed. Secondly, bituminous coal image of SEM was analyzed with IPP software. We found that the pore number distribution of bituminous coal dropped down sharply at small pore and gentlely at large pore. So the bituminous coal pore mainly concentrated in the small size of pore, other size of pores are relatively few. Lastly, two-dimensional pore structure of bituminous coal was reconstructed with Matlab software based on Monte Carlo method. Reconstruction of fixed diameter method showed that diameter of 15 pixel achieved the best of pore parameters. Fractal dimension of pore and pore number distribution with pore diameter are closer to the real pore structure. With the increasing of the reconstructing circle diameter, fractal dimension decreased