高温空气燃烧炉内燃烧特性的数值研究

Numerical Simulation of Combustion Characteristics in High Temperature Air Combustion Furnace

采用数值模拟法,研究了高温空气燃烧炉内不同空气预热温度、氧气浓度和燃气入口温度对火焰特性和NOx生成和排放的影响规律。研究表明,在提高空气预热温度、降低氧气浓度条件下,在较大范围内进行燃烧,火焰体积变大,炉内温度的峰值相应降低,温度分布更均匀,NOx的生成量大幅度降低。提高燃气入口温度,可抑制燃料和空气在主燃烧区的混合,使火焰内反应物的分布更加均匀,抑制了热力NO的生成,从而减少了NOx的排放量。

The influences of different air preheating temperature, oxygen concentration, and fuel inlet temperature on flame properties and NOx formation/emission in furnace were studied by numerical simulation. The results showed the combustion proceed within a larger zone by improving air preheating temperature and decreasing oxygen concentration, the flame volume get larger, the peak temperature become lower, and the NOx formation reduce remarkably. Moreover, increasing of fuel inlet temperature will lessen the mixing of the fuel and air in primary combustion zone, so the reactants distribution is more uniform and NOx emission is reduced greatly.