不同氧气浓度下CH4旋流燃烧器燃烧特性的数值模拟

对一种新型强制鼓风式燃烧器在不同O2浓度下的燃烧特性进行了研究,O2浓度分别为21%、23%、25%、27%、29%和31%。对燃烧器测试炉的炉膛内部温度分布和NOx生成情况进行了分析,并通过实验验证了模拟方法的准确性。研究结果表明:随着O2浓度的增加,测试炉膛内部火焰温度升高,炉膛温度分布均匀性变差,火焰最高温度位置前移,火焰整体长度增加,测试炉膛内部NOx浓度相应升高;当O2浓度低于27%时NOx的增长速率较为缓慢,当O2浓度高于27%时NOx的增长速率变大。因此,对于该燃烧器将O2浓度控制在27%以下可以有效地减少NOx的排放。

Numerical Simulation of the Combustion Characteristics of a Methane Swirling Burner at Various Oxygen Concentrations

Studied were the combustion characteristics of a novel forced blowing type burner at various oxygen concentrations of 21%,23%,25%,27% and 29% respectively.On this basis,the temperature distribution and NOx production inside the furnace of a boiler for testing burners were analyzed and the accuracy of the simulation method was verified through the tests.It has been found that with an increase of the oxygen concentration,the flame temperature inside the furnace tested will go up,the uniformity of the distribution of the temperature inside the furnace will become worsened,the location of the highest temperature of the flame will shift forward,the overall length of the flame will become lengthened and the NOx concentration inside the furnace tested will rise accordingly.When the oxygen concentration is lower than 27%,the growth rate of NOx will be relatively slow.When the oxygen concentration is higher than 27%,the growth rate of NOx will become big,therefore,for the burners under discussion,to control the oxygen concentration to be below 27% can effectively reduce the NOx emissions.