循环流化床中石油焦与煤混合燃烧N2O排放特性研究

在一座0.5MW循环流化床热态试验装置上进行了石油焦与煤混合燃烧试验,研究了烟气中N_2O的排放特性。对于石油焦与煤不同的燃料配比,不同的锅炉运行参数,如一次风率、过量空气系数、床温和Ca/S比等对烟气中N_2O排放浓度的影响规律进行了研究。试验表明,对于混合燃料,随焦煤比增大,N_2O排放浓度增高;对纯焦而言,其N_2O排放浓度最低。对于不同焦煤比的燃料,随着一次风率的增大,N_2O排放浓度增高。随过量空气系数增大,N_2O的排放浓度增加。无论焦煤比是1:1或3:1的燃料,当床温升高时,N_2O的排放浓度减小,且随焦煤比的增大,受床温的影响更敏感。焦煤比为1:1的混合燃料,随Ca/S比增加,N_2O排放浓度增高。

A RESEARCH ON N2O EMISSION OF PETROLEUM COKE COMBUSTION BLENDING WITH COAL IN CFB

Systematic combustion experiments of mixed fuels with different ratios of petroleum coke over coal are conducted on a 0.5MW_t pilot-scale CFB facility. The effects of various parameters, in terms of the ratio of petroleum coke over coal, the excess air coefficient, the bed temperature, the primary air fraction, the Ca/S ratio on the N_2O emission in the flue gas are revealed in this paper. It indicates from the experiments that with increasing in the ratio of petroleum coke over coal, N_2O emission concentration rises. For puree petroleum coke as fuel, N_2O emission concentration is the lowest than other mixed fuels. It is shown from experimental results that for all fuel mixtures with the primary air fraction, the excess air coefficient and the Ca/S ratio increasing, N_2O concentration rises. When the bed temperature increases, the N_2O concentration drops.