精细水煤浆的颗粒分形特征对燃烧特性的影响规律

利用神华、兖州和淮南3种煤制备了精细水煤浆，并对精细煤粉颗粒的粒度分布与表面分形特征、精细水煤浆的流变特性和不同升温速率下的燃烧特性进行了研究。结果表明随着精细煤粉的表面分形维数增大，其比表面积增大，粒度、孔径均相应减小，相同浓度下的精细浆的表观黏度值上升，精细水煤浆的着火温度和燃烧反应活化能降低。其中表观黏度值以淮南精细浆与兖州精细浆增加较多，在100 s^-1下都增加了740 mPa·s。着火温度和燃烧反应活化能都以淮南精细浆降低最多，其着火温度降低了41.36℃，燃烧反应活化能降低了77.71 kJ·kmol^-1。

Impact of particle fractal dimension of ultra-clean micronized coal water slurry on its combustion characteristics

The particle size values of three ultra-clean micronized coal water slurry, Huainan, Yanzhou, Shenhua, were measured with Malvern Mastersizer 2000 laser mastersizer.Their combustion characteristics were investigated with TGA/SDTA851e/LF1 1600 thermobalance at heating rates of 12.5, 25, 33.3 and 50 ℃·min^-1.Their apparent viscosities were measured with HAAKE VT550 viscometer.The specific area and pore diameter of the ultra-clean micronized coal powder were analyzed with Autosorb-1-C physisorption analysis instrument.Experimental investigation and theoretical analysis proved that the specific area of the ultra-clean micronized coal powder increased while pore diameter and particle size decreased with increasing fractal dimension.The apparent viscosity of the ultra-clean micronized coal water slurry increased with increasing fractal dimension.The ignition temperature and apparent activation energy of the ultra-clean micronized coal water slurry decreased with increasing fractal dimension.The ignition temperature of Huainan ultra-clean micronized coal water slurry decreased by 41.36℃ and its apparent activation energy decreased by 77.71 kJ·kmol^-1.