To further advance pulverized coal (PC) combustion theory and enable the rational development of horizontal bias combustion technology, combustion experiments were conducted in a 250 kW pilot-scale bias combustion simulator; multiple research means of combustion temperatures, flame spectra, burnout rates of residual solids, and NO_x formation were used. A blend of sub-bituminous coal from Indonesia and bituminous coal from Australia was tested. The effects of bias concentration ratio (BCR) on the ignition characteristics of parallel bias PC jets in a reducing atmosphere were investigated. The results indicate that with increasing BCR for parallel bias PC jets, the standoff distance gradually decreased; the peaks of subsequent combustion temperature and visible-light intensity gradually increased; the continuous flame regions became advanced and concentrated; the flame stability gradually increased; the burnout rate gradually increased; the NO_x formation gradually decreased, and the ignition characteristics gradually improved. Except at a BCR of 1, the PC ignition of the fuel-rich jet was better than that of the fuel-lean jet, and the continuous flame region of parallel bias PC jets leaned obviously in the direction of the fuel-rich jet. The bias combustion changed the ignition mode of primary air PC jets. There was homogeneous ignition mode at a BCR of 1; when BCR increased to no less than 3, the ignition mode changed to homogeneous–heterogeneous combined ignition, which is beneficial to the PC ignition conditions. Based on the research results in this paper, the recommended BCR for the design of a horizontal bias combustion PC burner is 4–5.

中文翻译：

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偏差浓度比对平行偏差煤粉喷射器点火特性的影响

为了进一步发展煤粉燃烧理论并合理发展水平偏向燃烧技术，我们在250 kW的中试偏向燃烧模拟器中进行了燃烧实验。多种研究手段，包括燃烧温度，火焰光谱，残留固体燃尽率和NO _x使用地层。对印度尼西亚的次烟煤和澳大利亚的烟煤的混合物进行了测试。研究了偏压浓度比（BCR）对还原性气氛中平行偏压PC射流着火特性的影响。结果表明，随着平行偏压PC射流的BCR的增加，对峙距离逐渐减小。随后的燃烧温度和可见光强度的峰值逐渐增大。连续的火焰区域变得先进并集中；火焰稳定性逐渐提高；倦怠率逐渐提高；该NO _X形成逐渐减少，并且点火特性逐渐改善。除了在BCR为1时，富燃料喷射的PC点火要比贫燃料喷射的PC点火好，并且平行偏置PC喷射的连续火焰区域明显朝着富燃料喷射的方向倾斜。偏向燃烧改变了一次空气PC射流的点火方式。BCR为1时，存在均匀点火模式；当BCR增大到不小于3时，点火模式变为均质-非均质组合点火，这有利于PC点火条件。根据本文的研究结果，设计水平偏置燃烧PC燃烧器的推荐BCR为4–5。