生物质及其与煤掺烧的灰熔融特性研究

STUDY ON FUSION BEHAVIOR OF ASH FROM MIXEDLY BURNING BOIMASS WITH COAL

采用YX-HRD灰熔融性测定仪对麦秆、稻秆、杨木屑等7种常见的生物质灰及其与煤掺烧后灰的熔融特性进行了检测。结果表明:煤的结渣判别指数不能完全、可靠地预测生物质及其与煤掺烧的结渣特性。根据生物质灰成分,对灰熔融温度的Pearson相关系数推导出生物质结渣判别指数A=(MgO+Al2O3+Fe2O3)/(CaO+P2O5)。生物质的加入在不同程度上降低了煤的灰熔点,在低配比范围内随生物质添加量的增多掺混煤灰熔点逐渐降低。随秸秆类生物质掺混比增加,碱金属氧化物含量增加使掺混煤灰熔点降低的作用减弱,但同时A值却较高,因而混煤灰熔点反而升高。秸秆类生物质的掺混比例在20%以下,酒糟、花生壳与杨木屑的掺混比例分别在40%、60%、60%以下都可避免严重结渣。

By using YX-HRD type ash fusility detecter,the slagging behavior of seven common biomass ashes,such as ash of wheat stalks,rise stalks,and poplar wooden scraps etc.,as well as their mixedly burning ash with coal have been detected.Results show that the slagging distinguishable index of coal can＇t completely and reliably predict the slagging behavior of biomass ash and their mixdely burning ash with coal.Based on the composition of biomass ash,the slagging distinguishable index of biomass A=（MgO＋Al2O3＋Fe2O3）/（CaO＋P2O5） has been deducted for the Pearson correlation coefficient of ash fusion temperature.Addition of biomass can reduce the ash fusion point of coal in different degrees.In a range of low proportioning ratio,the ash fusion point of mixed coal is gradually reduced as the addition of biomass is increased.Along with the increasing of proporting ratio of mixed stalks like biomass,the oxide content of alkaline metalls increases,making the effect of reducing ash fusion point of mixed coal to be weakened,but at the same time,the A value is higher,thereby the ash fusion point of mixed coal is heightened on the contrary.When the proportioning ratio of mixed stalks like biomass is less than 20%,and the mixed proportioning ratio of distiller＇s grain,peanut shells,and poplar wooden scraps being less than 40%,60%,and 60% respectively,the serious slagging phenomenon can all be avoided.