再燃中超细煤粉热解机理及挥发份释放的数值模拟

在煤粉再燃还原NO的过程中,挥发份的释放过程对其再燃还原NO有重要影响。对立式管式携带炉内再燃还原NO过程中超细煤粉热解化学机理及挥发份的释放进行了分析和数值模拟研究。再燃煤粉为100目筛下和320目筛下两种粒度的混煤煤粉。计算结果表明:在相同的条件下,粒度较细的煤粉升温速率较高;挥发份释放总量大;各挥发份组成物质释放早,在50ms内都已经基本释放完毕,其中CO2 释放速率最快,其次是CH4,再其次是C2H4、CO、HCN、H、NH,C2H6 释放速率最慢。使用超细煤粉作为再燃燃料,较常规煤粉更有利。图4表4参13

Numerical Simulations of the Pyrolysis Chemism and the Release Process of Volatiles During Recombustion of Micronized Coal

The release process of volatiles has a vital influence on the reduction of NOx during recombustion of pulverized coal. An analytical study and numerical simulation of the pyrolysis chemism and the release of volatiles of micronized coal, accompanying NOx reduction during its recombustion in EFR, has been conducted. A mixture of pulverized coal of 2 size ranges, respectively obtained with a 100 and a 320 mesh sieve, was taken for recombustion, Calculation results show that, under some conditions, the temperature risesquicker in case of finer granules, more voltiles are released in toto, and all the volatile ocmponents are released earlier, basically finished within 50 ms; the quickest being CO_2, followed in turn by CH_4,C_2H_4, CO, HCN, H,NH_3 with C_2H_6 hoving the smallest rate of release. It is more favourable for recombustion to use micromized coal instead of conventional pulverized coal.Figs 4, tables 4 and refs 13.