441 / 2018-12-30 05:11:58

双级引射全预混低氮燃烧器的结构设计与数值分析；Structural Design and Numerical Analysis of Two-stage Ejection Full Premixed Burner with Low-NOx emission

双级引射；全预混燃烧器；数值模拟；低氮排放；Two-stage ejection; Full premixed burner; Numerical simulation; Low-NOx emission

全体主题 > 数值模拟、建模与CFD

在全预混燃烧器的设计中加入引射器结构后，将大大减少其风机耗电，因此研究开发双级引射全预混低氮燃烧器颇有价值。本文首先设计了一款双级引射全预混低氮燃烧器的结构形式并对其具体尺寸进行了理论计算，进而对设计出的燃烧器建立三维、稳态的数学模型；然后利用计算流体力学（CFD）软件对燃烧器进行了模拟计算，探究了燃烧器内流场、温度场以及燃烧器喷口处CO与NOx浓度场的分布，校核了双级引射结构的引射系数，并研究了燃烧器负荷、一次引射系数、火孔大小、炉膛背压4个因素对燃烧器燃烧与排放性能的影响。研究结果表明：本设计的燃烧器结构合理，流场、温度场场分布均匀；双级引射结构可以实现混合气的过量空气系数稳定于1.05左右，从而实现全预混燃烧；燃烧器排放产物中几乎没有CO，NOx排放稳定低于30mg/m3。
The ejection structure can greatly reduce the power consumption of the fan for full premixed burner, so it is valuable to develop a two-stage ejection full premixed burner with low-NOx emission. In this paper, the structure of a two-stage ejection full premixed low-NOx burner was proposed and its specific dimensions were calculated. A three-dimensional and steady state mathematical model was established. Then the combustion and pollutant emission characteristics of the burner were numerically investigated using FLUENT 16.0. The results showed that the structure of the burner was reasonable. The flow field and the temperature field were evenly distributed. The two-stage ejector structure could achieve the excess air coefficient of the mixture stabilized at about 1.05, thus achieving full premixed combustion. In addition, the burner could realize fully burning and there was almost no CO in the burner discharge products, and the NOx emission was stable below 30mg/m3.