Low NOx boiler
    4.
    发明公开
    Low NOx boiler 失效
    Kessel mit vermindertem NOx-Ausstoss。

    公开(公告)号:EP0376259A2

    公开(公告)日:1990-07-04

    申请号:EP89123973.3

    申请日:1989-12-27

    摘要: A low-NOx boiler comprises a burner for burning gaseous fuel, heat transfer pipes (117) heating water by combustion heat of the burner to generate steam and having a passage (131) through which water flows, a steam drum (128) communicating with the heat transfer pipe and accumulating the steam from the heat transfer pipe, and an exhaust gas duct (114) located in the furnace to exhaust combustion gas generated by combustion of gaseous fuel outside of the boiler. The boiler further comprises unburnt gas burner (126) in the exhaust gas duct (114) for burning unburnt content in the combustion gas flowing in the duct. The unburnt gas burner includes a nozzle (2) for inject­ing premixture flow of fuel and combustion air and flame holding plate (1) located near the downstream side of the outlet of the nozzle to interrupt the premixture flow to form a circulating flow on downstream side of the flame holding plate. As gaseous fuel and air are mixed in advance and a flame is formed, the flame length can be shortened. Furthermore, the flame holding plate enables to reduce NOx generated. Unburnt gas burner pro`vided in the exhaust gas duct makes it possible to notably reduce the concentration of NOx discharged to the outside of the system.

    摘要翻译: 低NOx锅炉包括用于燃烧气体燃料的燃烧器,传热管(117)通过燃烧器的燃烧热量加热水以产生蒸汽并具有水流过的通道(131),蒸汽鼓(128)与 传热管和来自传热管的蒸汽积聚,并且位于炉中的排气管道(114)排出由锅炉外部的气体燃料燃烧产生的燃烧气体。 锅炉还包括废气管道(114)中的未燃气体燃烧器(126),用于燃烧在管道中流动的燃烧气体中的未燃烧物质。 未燃气体燃烧器包括用于喷射燃料和燃烧空气的预混合物流的喷嘴(2)和位于喷嘴出口下游侧附近的火焰保持板(1),以中断预混合流在下游侧形成循环流 的火焰保持板。 由于气体燃料和空气预先混合并形成火焰,因此可以缩短火焰长度。 此外,火焰保持板能够减少生成的NOx。 废气管道中的无燃气体燃烧器使得可以显着地降低排放到系统外部的NOx的浓度。