煤粉燃烧器的分级浓缩

一次风的浓缩有利于煤粉气流的着火、稳燃和降低NOx排放，是煤粉燃烧器一个主要任务。介绍浓淡燃烧器的工作原理，通过对燃烧器的浓缩过程的分级解析，说明分级浓缩是提高煤粉浓度的有效方法。有效的第1级浓缩增大了煤粉的输送浓度，进而可改善第2级浓缩．提高燃烧区的煤粉空间浓度。讨论了第1级和第2级浓缩对燃烧器性能的不同影响，说明了第2级浓缩的重要性和设计中应注意的一些事项，并提出煤粉燃烧器的第2级浓缩和其后的一、二次风的配合是保证燃烧器性能的关键，也是未来煤粉燃烧器的研究重点。

Multi-stage particulate concentration enrichment used in P-C boilers

Particulate concentration enrichment (PCE) of primary air in pulverized-coal (P-C) boilers is important to flame ignition, stabilization and low NOx emission. The principle of dense-dilute type burner is introduced. By analyzing the PCE process, it is concluded that multi-stage PCE is an effective way to increase spatial particle concentration. The effective first-stage PCE increased the coal transmission density, improved the second-stage PCE and raised the coal spatial concentration in burning zone. Influences on burner performance by the first and second-stage PCE are discussed, the importance of the second-stage PCE and some considerable items in designing are presented. The authors also promote that the matching of second-stage PCE and both primary and secondary air is a dominant factor for burner performance and a stress for future burner research.