外直流内旋流同轴射流和二次风平行射流组燃烧器流动特性的研究

某电厂410 t h燃油锅炉改烧水煤浆的改造工程中,采用了外直流内旋流同轴射流和二次风平行射流组的燃烧器结构,针对该结构的单角燃烧器流动特性进行了冷态模化试验与数值模拟研究。研究结果表明:一次风喷口与中心风喷口采用外直流内旋流同轴混合射流的形式,具有很好的调节作用,有利于水煤浆的稳定着火;二次风喷口采用上下平行射流的布置方式,除了可以补充足够的空气保证燃烧外,适当的射流速度可以防止脱火和回火现象的发生,有利于稳定燃烧。图10表1参5

Research on Flow Characteristics of Burners with Jets Having External-Straight and Internal-Swirling Coaxial Flow Matched with Parallel Secondary Air Jet Groups

In the reconstruction project of a 410 t/h boiler, where oil firing was changed to CWS firing, burners with externally straight and internally swirling coaxial jets matched with parallel secondary air jet groups were employed. Cold model tests and numerical simulation studies on flow characteristics of single corner burners, featured by the above mentioned structure, were conducted. Results show that primary air nozzles and center air nozzles with a jet flow resulting from a mixture of coaxial externally direct and internally swirling jet have good modulation properties, favorable for ignition of CWS. Upper and lower jets in parallel were used for secondary air, which, besides serving the purpose of providing sufficient air for combustion, also prevent flame disruption and back firing by choosing a proper jetting velocity, beneficial for stabilizing combustion. Figs 10, table 1 and refs 5.