分级燃烧低氮燃烧器的数值模拟与结构改进

Numerical Simulation and Structural Improvement of Low Nitrogen Burner with Staged Combustion

对基于分级燃烧技术的8 MW和15 MW燃气低NO_(x)燃烧器开展了数值模拟,分析了35%、70%和100%额定负荷三个运行工况下燃烧器温度场、组分浓度场和NO_(x)排放量等特性。燃烧器在各模拟工况下均表现出较好的燃尽特性和低于30 mg/m 3(3.5%O 2浓度换算)的NO_(x)排放量。针对15 MW燃烧器满负荷工作时炉膛前端近壁面设备烧损问题提出了两种改造方案,模拟结果表明改进后的方案解决了设备烧损问题,同时保证了低浓度的NO_(x)排放。

The computational fluid dynamics(CFD)software FLUENT is used to simulate the 8 MW and 15 MW gas-fired low NO_(x)burners based on staged combustion technology.The temperature field,component concentration field and NO_(x)emission characteristics of the two burners under three operating load of 35%,70%and 100%are analyzed.The burner has ideal burnout characteristics and the NO_(x)emission simulated to be less than 30 mg/m 3(conversion of 3.5%O 2 concentration)under all simulated conditions.In order to prevent the equipment at the front end of the furnace near the wall from being burned when the 15 MW burner is working at full load,two modified schemes are put forward.The simulation results show that the modified scheme solves the problem of equipment being damaged and ensures low concentration NO_(x)emission.